phosphoacceptor receiver (REC) domain of response regulators (RRs) and pseudo response regulators (PRRs); Two-component systems (TCSs) involving a sensor and a response regulator are used by bacteria to adapt to changing environments. Processes regulated by two-component systems in bacteria include sporulation, pathogenicity, virulence, chemotaxis, and membrane transport. Response regulators (RRs) share the common phosphoacceptor REC domain and different effector/output domains such as DNA, RNA, ligand-binding, protein-binding, or enzymatic domains. Response regulators regulate transcription, post-transcription or post-translation, or have functions such as methylesterases, adenylate or diguanylate cyclase, c-di-GMP-specific phosphodiesterases, histidine kinases, serine/threonine protein kinases, and protein phosphatases, depending on their output domains. The function of some output domains are still unknown. TCSs are found in all three domains of life - bacteria, archaea, and eukaryotes, however, the presence and abundance of particular RRs vary between the lineages. Archaea encode very few RRs with DNA-binding output domains; most are stand-alone REC domains. Among eukaryotes, TCSs are found primarily in protozoa, fungi, algae, and green plants. REC domains function as phosphorylation-mediated switches within RRs, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   6 LVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNswLTTEIPIILLTGL 85
Cdd:cd00156     1 LIVDDDPAIRELLKSLLEREGYEVDTAADGEEALELLREERPDLVLLDLMMPGMDGLELLRKLRE--LPPDIPVIVLTAK 78

                          90       100
                  ....*....|....*....|.
gi 1821198215  86 SH--QKISEFDCQADAILGKP 104
Cdd:cd00156    79 ADeeDAVRALELGADDYLVKP 99

osmolarity response regulator; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   2 NKKILVVDDDLfMLRS-LELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNSwlTTEIPII 80
Cdd:PRK09468    5 NYKILVVDDDM-RLRAlLERYLTEQGFQVRSAANAEQMDRLLTRESFHLMVLDLMLPGEDGLSICRRLRSQ--NNPTPII 81

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|.
gi 1821198215  81 LLT--GLSHQKISEFDCQADAILGKPCNYDTLLHTISDLLK 119
Cdd:PRK09468   82 MLTakGEEVDRIVGLEIGADDYLPKPFNPRELLARIRAVLR 122

CheY-like REC (receiver) domain, includes chemotaxis protein CheY and sporulation regulator Spo0F [Signal transduction mechanisms];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   1 MNKKILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNSWLTTEIPII 80
Cdd:COG0784     4 GGKRILVVDDNPDNRELLRRLLERLGYEVTTAEDGAEALELLRAGPPDLILLDINMPGMDGLELLRRIRALPRLPDIPII 83

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|.
gi 1821198215  81 LLTGLSHQKISE--FDCQADAILGKPCNYDTLLHTISDLLK 119
Cdd:COG0784    84 ALTAYADEEDREraLEAGADDYLTKPVDPEELLEALRRLLA 124

DNA-binding transcriptional response regulator, NtrC family, contains REC, AAA-type ATPase, and a Fis-type DNA-binding domains [Signal transduction mechanisms];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   1 MNKKILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNSWLttEIPII 80
Cdd:COG2204     1 SMARILVVDDDPDIRRLLKELLERAGYEVETAASGEEALALLREEPPDLVLLDLRMPGMDGLELLRELRALDP--DLPVI 78

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|.
gi 1821198215  81 LLTGLSHQKISE--FDCQADAILGKPCNYDTLLHTISDLLK 119
Cdd:COG2204    79 LLTGYGDVETAVeaIKAGAFDYLTKPFDLEELLAAVERALE 119

phosphoacceptor receiver (REC) domain of response regulators (RRs) and pseudo response regulators (PRRs); Two-component systems (TCSs) involving a sensor and a response regulator are used by bacteria to adapt to changing environments. Processes regulated by two-component systems in bacteria include sporulation, pathogenicity, virulence, chemotaxis, and membrane transport. Response regulators (RRs) share the common phosphoacceptor REC domain and different effector/output domains such as DNA, RNA, ligand-binding, protein-binding, or enzymatic domains. Response regulators regulate transcription, post-transcription or post-translation, or have functions such as methylesterases, adenylate or diguanylate cyclase, c-di-GMP-specific phosphodiesterases, histidine kinases, serine/threonine protein kinases, and protein phosphatases, depending on their output domains. The function of some output domains are still unknown. TCSs are found in all three domains of life - bacteria, archaea, and eukaryotes, however, the presence and abundance of particular RRs vary between the lineages. Archaea encode very few RRs with DNA-binding output domains; most are stand-alone REC domains. Among eukaryotes, TCSs are found primarily in protozoa, fungi, algae, and green plants. REC domains function as phosphorylation-mediated switches within RRs, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   6 LVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNswLTTEIPIILLTGL 85
Cdd:cd00156     1 LIVDDDPAIRELLKSLLEREGYEVDTAADGEEALELLREERPDLVLLDLMMPGMDGLELLRKLRE--LPPDIPVIVLTAK 78

                          90       100
                  ....*....|....*....|.
gi 1821198215  86 SH--QKISEFDCQADAILGKP 104
Cdd:cd00156    79 ADeeDAVRALELGADDYLVKP 99

phosphoacceptor receiver (REC) domain of cyclic di-GMP phosphodiesterase PA4781 and similar domains; Pseudomonas aeruginosa cyclic di-GMP phosphodiesterase PA4781 contains an N-terminal REC domain and a C-terminal catalytic HD-GYP domain, characteristics of RpfG family response regulators. PA4781 is involved in cyclic di-3',5'-GMP (c-di-GMP) hydrolysis/degradation in a two-step reaction via the linear intermediate pGpG to produce GMP. Its unphosphorylated REC domain prevents accessibility of c-di-GMP to the active site. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   5 ILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNSWLTTEIPIILLTG 84
Cdd:cd19920     1 ILIVDDVPDNLRLLSELLRAAGYRVLVATDGQQALQRAQAEPPDLILLDVMMPGMDGFEVCRRLKADPATRHIPVIFLTA 80

                  ..
gi 1821198215  85 LS 86
Cdd:cd19920    81 LT 82

phosphoacceptor receiver (REC) domain of uncharacterized hybrid sensor histidine kinase/response regulators; Typically, two-component regulatory systems (TCSs) consist of a sensor (histidine kinase) that responds to specific input(s) by modifying the output of a cognate response regulator (RR). TCSs allow organisms to sense and respond to changes in environmental conditions. Hybrid sensor histidine kinase/response regulators contain all the elements of a classical TCS in a single polypeptide chain. RRs share the common phosphoacceptor REC domain and different effector/output domains such as DNA, RNA, ligand-binding, protein-binding, or enzymatic domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   5 ILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNSWLTTEIPIILLTG 84
Cdd:cd17598     1 ILIVEDSPTQAEQLKHILEEQGYKVQVARNGREALAMLAEHRPTLVISDIVMPEMDGYELCRKIKSDPDLKDIPVILLTT 80

                          90       100       110
                  ....*....|....*....|....*....|....*.
gi 1821198215  85 LS--HQKISEFDCQADAILGKPCNYDTLLHTISDLL 118
Cdd:cd17598    81 LSdpRDVIRGLECGADNFITKPYDEKYLLSRIKYIL 116

Stage 0 sporulation initiation response regulator Spo0F [Cell cycle control, cell division, chromosome partitioning, Signal transduction mechanisms];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   1 MNKKILVVDDDLFMLRSLELLLSDEGYIVHLVdkSSLIK--ESIVAFNPDLIVMDIRLDDADGREICDKIKNSWltTEIP 78
Cdd:COG5803     1 MMKKILIVDDQAGIRMLLKEVLKKEGYEVFQA--ANGKEalEKVKELKPDLVLLDMKMPGMDGIEILKEIKEID--PDIP 76

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|...
gi 1821198215  79 IILLTGLSHQ-KISEFDCQ-ADAILGKPCNYDTLLHTISDLLK 119
Cdd:COG5803    77 VIMMTAYGELdMVEEAKELgAKGYFTKPFDIDELREAVNKLLK 119

phosphoacceptor receiver (REC) domain of modulated diguanylate cyclase and similar domains; This groups includes a modulated diguanylate cyclase containing a PAS sensor domain from Desulfovibrio desulfuricans G20. Members of this group contain N-terminal REC domains and various output domains including the GGDEF, histidine kinase, and helix-turn-helix (HTH) DNA binding domains. Also included in this family is Mycobacterium tuberculosis PdtaR, a transcriptional antiterminator that contains a REC domain and an ANTAR RNA-binding output domain. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   3 KKILVVDDDLFMLRSLELLLSDEGY-IVHLVDKSSLIKESIVAFNPDLIVMDIRL-DDADGREICDKIKNSWlttEIPII 80
Cdd:cd17534     1 KKILIVEDEAIIALDLKEILESLGYeVVGIADSGEEAIELAEENKPDLILMDINLkGDMDGIEAAREIREKF---DIPVI 77

                          90       100       110
                  ....*....|....*....|....*....|....*.
gi 1821198215  81 LLTGLSHQKISE--FDCQADAILGKPCNYDTLLHTI 114
Cdd:cd17534    78 FLTAYSDEETLEraKETNPYGYLVKPFNERELKAAI 113

phosphoacceptor receiver (REC) domain of PmrA-like OmpR family response regulators; This subfamily contains various OmpR family response regulators including PmrA, BasR, QseB, tctD, and RssB, which are components of two-component regulatory systems (TCSs). The PmrA/PmrB TCS controls transcription of genes that are involved in lipopolysaccharide modification in the outer membrane of bacteria, increasing bacterial resistance to host-derived antimicrobial peptides. The BasS/BasR TCS functions as an iron- and zinc-sensing transcription regulator. The QseB/QseC TCS activates the flagella regulon by activating transcription of FlhDC. The RssA/RssB TCS regulates swarming behavior in Serratia marcescens. OmpR family DNA-binding response regulators contain N-terminal receiver (REC) and C-terminal DNA-binding winged helix-turn-helix effector domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   5 ILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNSWLTTeiPIILLTG 84
Cdd:cd17624     1 ILLVEDDALLGDGLKTGLRKAGYAVDWVRTGAEAEAALASGPYDLVILDLGLPDGDGLDLLRRWRRQGQSL--PVLILTA 78

                          90       100
                  ....*....|....*....|..
gi 1821198215  85 LS--HQKISEFDCQADAILGKP 104
Cdd:cd17624    79 RDgvDDRVAGLDAGADDYLVKP 100

phosphoacceptor receiver (REC) domain of PrrA-like OmpR family response regulators; The Mycobacterium tuberculosis PrrA is part of the PrrA/PrrB two-component system (TCS) that has been implicated in early intracellular multiplication and is essential for viability. Also included in this subfamily is Mycobacterium tuberculosis MprA, part of the MprAB TCS that regulates EspR, a key regulator of the ESX-1 secretion system, and is required for establishment and maintenance of persistent infection in a tissue- and stage-specific fashion. PrrA and MprA belong to the OmpR family of DNA-binding response regulators, which contain N-terminal receiver (REC) and C-terminal DNA-binding winged helix-turn-helix effector domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   5 ILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNSwlTTEIPIILLTG 84
Cdd:cd17627     1 ILVVDDDRAVRESLRRSLRFEGYEVETAVDGAEALRVISGNRPDAVVLDVMMPRLDGLEVCRRLRAA--GNDLPILVLTA 78

                          90       100       110
                  ....*....|....*....|....*....|....*..
gi 1821198215  85 LSH--QKISEFDCQADAILGKPCNYDTLLHTISDLLK 119
Cdd:cd17627    79 RDSvsDRVAGLDAGADDYLVKPFALEELLARVRALLR 115

phosphoacceptor receiver (REC) domain of YrcF-like OmpR family response regulators; YycF appears to play an important role in cell wall integrity in a wide range of gram-positive bacteria, and may also modulate cell membrane integrity. It functions as part of a phosphotransfer system that ultimately controls the levels of competence within the bacteria. YycF belongs to the OmpR family of response regulators, which are characterized by a REC domain and a winged helix-turn-helix effector domain involved in DNA binding. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   5 ILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNswlTTEIPIILLTG 84
Cdd:cd17614     1 ILVVDDEKPISDILKFNLTKEGYEVVTAYDGREALEKVEEEQPDLILLDLMLPEKDGLEVCREVRK---TSNVPIIMLTA 77

                          90
                  ....*....|
gi 1821198215  85 lshqKISEFD 94
Cdd:cd17614    78 ----KDSEVD 83

phosphoacceptor receiver (REC) domain of KdpE-like OmpR family response regulators; KdpE is a component of the KdpD/KdpE two-component system (TCS) and is activated when histidine kinase KdpD senses a drop in external K+ concentration or upshift in ionic osmolarity, resulting in the expression of a heterooligomeric transporter KdpFABC. In addition, the KdpD/KdpE TCS is also an adaptive regulator involved in the virulence and intracellular survival of pathogenic bacteria. KdpE is a member of the OmpR family of DNA-binding response regulators that contain REC and winged helix-turn-helix (wHTH) DNA-binding output effector domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   5 ILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKnSWltTEIPIILLTG 84
Cdd:cd17620     1 ILVIEDEPQIRRFLRTALEAHGYRVFEAETGQEGLLEAATRKPDLIILDLGLPDMDGLEVIRRLR-EW--SAVPVIVLSA 77

                          90       100
                  ....*....|....*....|..
gi 1821198215  85 LS--HQKISEFDCQADAILGKP 104
Cdd:cd17620    78 RDeeSDKIAALDAGADDYLTKP 99

DNA-binding response regulator DpiB of citrate/malate metabolism [Transcription, Signal transduction mechanisms];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   1 MNKKILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLI--KESIVAFNPDLIVMDIRLDDADGREICDKIKNswLTTEIP 78
Cdd:COG4565     2 KMIRVLIVEDDPMVAELLRRYLERLPGFEVVGVASSGEeaLALLAEHRPDLILLDIYLPDGDGLELLRELRA--RGPDVD 79

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|...
gi 1821198215  79 IILLTGLSHQKISE--FDCQADAILGKPCNYDTLLHTISDLLK 119
Cdd:COG4565    80 VIVITAARDPETVReaLRAGVVDYLIKPFTFERLREALERYLE 122

phosphoacceptor receiver (REC) domain of BsPhoP-like OmpR family response regulators; Bacillus subtilis PhoP (BsPhoP) is part of the PhoPR two-component system that participates in a signal transduction network that controls adaptation of the bacteria to phosphate deficiency by regulating (activating or repressing) genes of the Pho regulon upon phosphorylation by PhoR. When activated, PhoPR directs expression of phosphate scavenging enzymes, lowers synthesis of the phosphate-rich wall teichoic acid (WTA) and initiates synthesis of teichuronic acid, a non-phosphate containing replacement anionic polymer. Members of this subfamily belong to the OmpR family of DNA-binding response regulators, which are characterized by a REC domain and a winged helix-turn-helix (wHTH) DNA-binding output effector domain. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   6 LVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNSWLTTEIPIILLTGl 85
Cdd:cd19937     1 LVVDDEEDIVELLKYNLEKEGYEVVTAYDGEEALKRAKDEKPDLIILDLMLPGIDGLEVCRILRSDPKTSSIPIIMLTA- 79

                  ....*....
gi 1821198215  86 shqKISEFD 94
Cdd:cd19937    80 ---KGEEFD 85

phosphoacceptor receiver (REC) domain of MtrA-like OmpR family response regulators; MtrA is part of MtrA/MtrB (or MtrAB), a highly conserved two-component system (TCS) implicated in the regulation of cell division in the actinobacteria. In unicellular Mycobacterium tuberculosis, MtrAB coordinates DNA replication with cell division and regulates the transcription of resuscitation-promoting factor B. In filamentous Streptomyces venezuelae, it links antibiotic production to sporulation. MtrA belongs to the OmpR family of DNA-binding response regulators that contain N-terminal receiver (REC) and C-terminal DNA-binding winged helix-turn-helix effector domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   4 KILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKnswLTTEIPIILLT 83
Cdd:cd17626     2 RILVVDDDAALAEMIGIVLRGEGFDPAFCGDGTQALAAFREVRPDLVLLDLMLPGIDGIEVCRQIR---AESGVPIVMLT 78

                  ...
gi 1821198215  84 GLS 86
Cdd:cd17626    79 AKS 81

phosphoacceptor receiver (REC) domain of PhoB response regulator from the OmpR family; The transcription factor PhoB is a component of the PhoR/PhoB two-component system, a key regulatory protein network that facilitates response to inorganic phosphate (Pi) starvation conditions by turning on the phosphate (pho) regulon whose products are involved in phosphorus uptake and metabolism. PhoB is a member of the OmpR family of DNA-binding response regulators that contains REC and winged helix-turn-helix (wHTH) DNA-binding output effector domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   3 KKILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNSWLTTEIPIILL 82
Cdd:cd17618     1 RTILIVEDEPAIREMIAFNLERAGFDVVEAEDAESAVNLIVEPRPDLILLDWMLPGGSGIQFIRRLKRDEMTRDIPIIML 80

                          90       100
                  ....*....|....*....|....
gi 1821198215  83 TGLSHQ--KISEFDCQADAILGKP 104
Cdd:cd17618    81 TARGEEedKVRGLEAGADDYITKP 104

phosphoacceptor receiver (REC) domain of hybrid sensor histidine kinases/response regulators similar to Arabidopsis thaliana CKI1 and Escherichia coli RcsC; This family is composed of hybrid sensor histidine kinases/response regulators that are sensor histidine kinases (HKs) fused with a REC domain, similar to the sensor histidine kinase CKI1 from Arabidopsis thaliana, which is involved in multi-step phosphorelay (MSP) signaling that mediates responses to a variety of important stimuli in plants. MSP involves a signal being transferred from HKs via histidine phosphotransfer proteins (AHP1-AHP5) to nuclear response regulators. The CKI1 REC domain specifically interacts with the downstream signaling protein AHP2, AHP3 and AHP5. The plant MSP system has evolved from the prokaryotic two-component system (TCS), which allows organisms to sense and respond to changes in environmental conditions. This family also includes bacterial hybrid sensor HKs such as Escherichia coli RcsC, which is a component of the Rcs signalling pathway that controls a variety of physiological functions like capsule synthesis, cell division, and motility. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   5 ILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNSWLTTE-IPIILLT 83
Cdd:cd17546     1 VLVVDDNPVNRKVLKKLLEKLGYEVDVAENGQEALELLKEEPFDLVLMDLQMPVMDGLEATRRIRELEGGGRrTPIIALT 80

                          90       100       110
                  ....*....|....*....|....*....|...
gi 1821198215  84 G--LSHQKISEFDCQADAILGKPCNYDTLLHTI 114
Cdd:cd17546    81 AnaLEEDREKCLEAGMDDYLSKPVKLDQLKEVL 113

phosphoacceptor receiver (REC) domain of nitrogen assimilation regulatory protein NtrX and similar proteins; NtrX is part of the two-component regulatory system NtrY/NtrX that is involved in the activation of nitrogen assimilatory genes such as Gln. It is phosphorylated by the histidine kinase NtrY and interacts with sigma-54. NtrX is a member of the NtrC family, characterized by a domain architecture containing an N-terminal REC domain, followed by a central sigma-54 interaction/ATPase domain, and a C-terminal DNA binding domain. NtrC family response regulators are sigma54-dependent transcriptional activators. Also included in this subfamily is Aquifex aeolicus NtrC4. The ability of the central domain to hydrolyze ATP and thus to interact effectively with a complex of RNA polymerase, sigma54, and promoter, is controlled by the phosphorylation status of the REC domain. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   5 ILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNSWLttEIPIILLTG 84
Cdd:cd17550     1 ILIVDDEEDIRESLSGILEDEGYEVDTAADGEEALKLIKERRPDLVLLDIWLPDMDGLELLKEIKEKYP--DLPVIMISG 78

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|..
gi 1821198215  85 -------LSHQKISEFDcqadaILGKPCNYDTLLHTISDLLK 119
Cdd:cd17550    79 hgtietaVKATKLGAYD-----FIEKPLSLDRLLLTIERALE 115

cheY-homologous receiver domain; CheY regulates the clockwise rotation of E. coli flagellar motors. This domain contains a phosphoacceptor site that is phosphorylated by histidine kinase homologues.

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....
gi 1821198215    3 KKILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRL 56
Cdd:smart00448   1 MRILVVDDDPLLRELLKALLEKEGYEVDEATDGEEALELLKEEKPDLILLDIMM 54

phosphoacceptor receiver (REC) domain of BfmR-like OmpR family response regulators; Acinetobacter baumannii BfmR is part of the BfmR/S two-component system that functions as the master regulator of biofilm initiation. BfmR confers resistance to complement-mediated bactericidal activity, independent of capsular polysaccharide, and also increases resistance to the clinically important antimicrobials meropenem and colistin, making it a potential antimicrobial target. Its inhibition would have the dual benefit of significantly decreasing in vivo survival and increasing sensitivity to selected antimicrobials. Members of this subfamily belong to the OmpR family of DNA-binding response regulators, which are characterized by a REC domain and a winged helix-turn-helix (wHTH) DNA-binding output effector domain. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   4 KILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNSwltTEIPIILLT 83
Cdd:cd19939     1 RILIVEDELELARLTRDYLIKAGLEVSVFTDGQRAVRRIIDEQPSLVVLDIMLPGMDGLTVCREVREH---SHVPILMLT 77

                          90       100       110
                  ....*....|....*....|....*....|....*...
gi 1821198215  84 GLSHQ--KISEFDCQADAILGKPCNYDTLLHTISDLLK 119
Cdd:cd19939    78 ARTEEmdRVLGLEMGADDYLCKPFSPRELLARVRALLR 115

DNA-binding response regulator, FixJ family, consists of REC and HTH domains [Signal transduction mechanisms, Transcription];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   5 ILVVDDDLFMLRSLELLLSDEGYIVHLVdksslikESIVAF-------NPDLIVMDIRLDDADGREICDKIKNSWLTteI 77
Cdd:COG4566     2 VYIVDDDEAVRDSLAFLLESAGLRVETF-------ASAEAFlaaldpdRPGCLLLDVRMPGMSGLELQEELAARGSP--L 72

                  ....*..
gi 1821198215  78 PIILLTG 84
Cdd:COG4566    73 PVIFLTG 79

phosphoacceptor receiver (REC) domain of photosynthetic apparatus regulatory protein RegA; Rhodobacter sphaeroides RegA, also called response regulator PrrA, is the DNA binding regulatory protein of a redox-responsive two-component regulatory system RegB/RegA that is involved in transactivating anaerobic expression of the photosynthetic apparatus. It contains a REC domain and a DNA-binding helix-turn-helix output domain. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   3 KKILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNswLTTEIPIILL 82
Cdd:cd17563     1 KSLLLVDDDEVFAERLARALERRGFEVETAHSVEEALALAREEKPDYAVLDLRLGGDSGLDLIPPLRA--LQPDARIVVL 78

                  ..
gi 1821198215  83 TG 84
Cdd:cd17563    79 TG 80

DNA-binding response regulator, LytR/AlgR family [Transcription, Signal transduction mechanisms];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   4 KILVVDDDLFMLRSLELLLSDEGYIvHLVDKSSLIKESIVAFN---PDLIVMDIRLDDADGREICDKIKNswLTTEIPII 80
Cdd:COG3279     3 KILIVDDEPLARERLERLLEKYPDL-EVVGEASNGEEALELLEehkPDLVFLDIQMPGLDGFELARQLRE--LDPPPPII 79

                          90       100       110
                  ....*....|....*....|....*....|....*....
gi 1821198215  81 LLTGLSHQKISEFDCQADAILGKPCNYDTLLHTISDLLK 119
Cdd:COG3279    80 FTTAYDEYALEAFEVNAVDYLLKPIDEERLAKALEKAKE 118

phosphoacceptor receiver (REC) domain of BaeR-like OmpR family response regulators; BaeR is part of the BaeSR two-component system that is involved in regulating genes that confer multidrug and metal resistance. In Salmonella, BaeSR induces AcrD and MdtABC drug efflux systems, increasing multidrug and metal resistance. In Escherichia coli, BaeR stimulates multidrug resistance via mdtABC (multidrug transporter ABC, formerly known as yegMNO) genes, which encode a resistance-nodulation-cell division (RND) drug efflux system. Members of this subfamily belong to the OmpR family of DNA-binding response regulators, which are characterized by a REC domain and a winged helix-turn-helix (wHTH) DNA-binding output effector domain. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   4 KILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNSwltTEIPIILLT 83
Cdd:cd19938     1 RILIVEDEPKLAQLLIDYLRAAGYAPTLLAHGDQVLPYVRHTPPDLILLDLMLPGTDGLTLCREIRRF---SDVPIIMVT 77

                          90
                  ....*....|.
gi 1821198215  84 GlshqKISEFD 94
Cdd:cd19938    78 A----RVEEID 84

phosphoacceptor receiver (REC) domain of NarL (Nitrate/Nitrite response regulator L) family response regulators; The NarL family is one of the more abundant families of DNA-binding response regulators (RRs). Members of the NarL family contain a REC domain and a helix-turn-helix (HTH) DNA-binding output domain, with a majority of members containing a LuxR-type HTH domain. They function as transcriptional regulators. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   5 ILVVDDDLFMLRSLELLLS-DEGYIVhlVDKSSLIKESIVAFN---PDLIVMDIRLDDADGREICDKIKNSWLTTeiPII 80
Cdd:cd17535     1 VLIVDDHPLVREGLRRLLEsEPDIEV--VGEAADGEEALALLRelrPDVVLMDLSMPGMDGIEALRRLRRRYPDL--KVI 76

                          90       100       110
                  ....*....|....*....|....*....|....*.
gi 1821198215  81 LLTG-LSHQKISE-FDCQADAILGKPCNYDTLLHTI 114
Cdd:cd17535    77 VLTAhDDPEYVLRaLKAGAAGYLLKDSSPEELIEAI 112

phosphoacceptor receiver (REC) domain of chemotaxis protein CheY; The chemotaxis response regulator CheY contains a stand-alone REC domain. Chemotaxis is a behavior known for motile bacteria that directs their movement in response to chemical gradients. CheY is involved in transmitting sensory signals from chemoreceptors to the flagellar motors. Phosphorylated CheY interacts with the flagella switch components FliM and FliY, which causes counterclockwise rotation of the flagella, resulting in smooth swimming. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   3 KKILVVDDDLFMLRSLELLLSDEGYIVhlVDKSSLIKESIVAF---NPDLIVMDIRLDDADGREICDKIKNswLTTEIPI 79
Cdd:cd17542     1 KKVLIVDDAAFMRMMLKDILTKAGYEV--VGEAANGEEAVEKYkelKPDLVTMDITMPEMDGIEALKEIKK--IDPNAKV 76

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|.
gi 1821198215  80 ILLTGLSHQKISEFDCQADA--ILGKPCNYDTLLHTISDLL 118
Cdd:cd17542    77 IMCSAMGQEEMVKEAIKAGAkdFIVKPFQPERVLEAVEKVL 117

phosphoacceptor receiver (REC) domain of kpRstA-like OmpR family response regulators; Klebsiella pneumoniae RstA (kpRstA) is part of the RstA/RstB two-component regulatory system that may play a regulatory role in virulence. It belongs to the OmpR family of DNA-binding response regulators that contain N-terminal receiver (REC) and C-terminal DNA-binding winged helix-turn-helix effector domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1821198215   4 KILVVDDDLFMLRSLELLLSDEGYIVHLVDKSSLIKESIVAFNPDLIVMDIRLDDADGREICDKIKNSWlttEIPIILLT 83
Cdd:cd17622     2 RILLVEDDPKLARLIADFLESHGFNVVVEHRGDRALEVIAREKPDAVLLDIMLPGIDGLTLCRDLRPKY---QGPILLLT 78

                          90       100       110
                  ....*....|....*....|....*....|....*...
gi 1821198215  84 GLSHQ--KISEFDCQADAILGKPCNYDTLLHTISDLLK 119
Cdd:cd17622    79 ALDSDidHILGLELGADDYVVKPVEPAVLLARLRALLR 116