Plastocyanin is a type I copper protein and functions in the electron transfer from PSII to PSI; Plastocyanin is a small copper-containing protein found in cyanobacteria, higher plants, and some algae, where it plays a role in photosynthesis. The two photosystems that are primarily responsible for photosynthesis are photosystem I (PSI) and photosystem II (PSII). The flow of electrons begins in PSII, which acts as a proton pump. Plastocyanin is responsible for transporting electrons from PSII to PSI.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1965327819  69 LEVLLGGDDGSLAFIPREFSVSSGEKIVFKNNAGFPHNVVFDEDEVPSGVDASKISMpeEDLLNAPGETYAVTLTEKGSY 148
Cdd:cd04219     1 ATVKMGSDSGALVFEPKELTVKAGDTVEFVNNKGGPHNVVFDEDAVPSAVDAAALSH--KDLLNAPGETFSVTFPAPGTY 78

                          90
                  ....*....|....*....
gi 1965327819 149 SFYCSPHQGAGMVGKVTVN 167
Cdd:cd04219    79 TFYCEPHRGAGMVGKITVQ 97

Plastocyanin [Energy production and conversion];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1965327819  80 LAFIPREFSVSSGEKIVFKNNAGFPHNVVFDEDevPSGVDASKISmpeedllnAPGETYAVTLTEKGSYSFYCSPHqgAG 159
Cdd:COG3794     1 MAFEPATLTVKPGDTVTWVNTDSVPHNVTSDDG--PDGAFDSGLL--------APGETFSVTFDEPGTYDYYCTPH--PW 68

                  ....*..
gi 1965327819 160 MVGKVTV 166
Cdd:COG3794    69 MVGTIVV 75

Plastocyanin is a type I copper protein and functions in the electron transfer from PSII to PSI; Plastocyanin is a small copper-containing protein found in cyanobacteria, higher plants, and some algae, where it plays a role in photosynthesis. The two photosystems that are primarily responsible for photosynthesis are photosystem I (PSI) and photosystem II (PSII). The flow of electrons begins in PSII, which acts as a proton pump. Plastocyanin is responsible for transporting electrons from PSII to PSI.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1965327819  69 LEVLLGGDDGSLAFIPREFSVSSGEKIVFKNNAGFPHNVVFDEDEVPSGVDASKISMpeEDLLNAPGETYAVTLTEKGSY 148
Cdd:cd04219     1 ATVKMGSDSGALVFEPKELTVKAGDTVEFVNNKGGPHNVVFDEDAVPSAVDAAALSH--KDLLNAPGETFSVTFPAPGTY 78

                          90
                  ....*....|....*....
gi 1965327819 149 SFYCSPHQGAGMVGKVTVN 167
Cdd:cd04219    79 TFYCEPHRGAGMVGKITVQ 97

Small blue copper proteins including pseudocyanin, plastocyanin, halocyanin and amicyanin; The Pseudocyanin-like family of copper-binding proteins (or blue (type 1) copper domain) is a family of small proteins that bind a single copper atom and are characterized by an intense electronic absorption band near 600 nm. Pseudoazurin (PAz) has been identified as a electron donor in the denitrification pathway. For example, PAz acts as an electron donor to cytochrome c peroxidase and N2OR from Paracoccus pantotrophus (Pp), and to the copper containing nitrite reductase (NiR) that catalyzes the second step of denitrification. Plastocyanin is found in cyanobacteria, higher plants, and some algae where it plays a role in photosynthesis. Plastocyanin is responsible for transporting electrons from PSII to PSI. This family also includes halocyanins found in halophilic archaea such as Natronomonas pharaonis (Natronobacterium pharaonis) and amicyanin found in bacteria Paracoccus denitrificans.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1965327819  70 EVLLGGDDGSLAFIPREFSVSSGEKIVFKNNAGFPHNVVFDEDEVPSGVDASKismpeEDLLNAPGETYAVTLTEKGSYS 149
Cdd:cd04204     2 VVKMGADNGAMAFEPAAIRVDAGETVEFVNTGGGPHNVVFDKEIVPDGDAEFE-----SDRVDEEGFTYEQTFDEPGVYG 76

                          90
                  ....*....|....*.
gi 1965327819 150 FYCSPHQGAGMVGKVT 165
Cdd:cd04204    77 YYCTPHRGAGMVGTVI 92

Halocyanin is an archaea blue (type I) copper redox protein; Halocyanins are blue (type I) copper redox proteins found in halophilic archaea such as Natronomonas pharaonis (Natronobacterium pharaonis). Halocyanin may serve as a mobile electron carrier at a peripheral membrane protein. The copper-binding domain is present only once in some halocyanins and is duplicated in others.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1965327819  75 GDDGSLAFIPREFSVSSGEKIVFKNNA-GFPHNVVFDEDEVPSGVDASKISmpeedllnAPGETYAVTLTEKGSYSFYCS 153
Cdd:cd04220     7 GMNGGFAFDPAAIRVSPGTTVTWEWTGeGGGHNVVAYEDPITAFDSGSTDS--------SEGETYEHTFEETGEYRYVCV 78

                          90
                  ....*....|....
gi 1965327819 154 PHQGAGMVGKVTVN 167
Cdd:cd04220    79 PHEALGMKGAIVVE 92

Amicyanin is a type I blue copper protein that plays an essential role in electron transfer; In Paracoccus denitrificans bacteria, amicyanin acts as an intermediary of a three-member redox complex along with methylamine dehydrogenase (MADH) and cytochrome c-551i. The electron is transferred from the active site of MADH via the amicyanin copper ion to the cytochrome heme iron. The electron transfer from MADH to cytochrome c-551i does not involve a ternary complex but occurs via a ping-pong mechanism in which amicyanin uses the same interface for the reactions with MADH and cytochrome c-551i.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1965327819  79 SLAFIPREFSVSSGEKIVFKNNAGFPHNVVFDEDEVPSGvdaskismpeedlLNAPGETYAVTLTEKGSYSFYCSPHqgA 158
Cdd:cd13921     8 DFKFNPAEVTVKVGDTVTWTNKDSVPHTVTAEDGAFDSG-------------MLATGKSFSYTFTAAGTYDYFCTIH--P 72

                  ....*...
gi 1965327819 159 GMVGKVTV 166
Cdd:cd13921    73 FMKGTVTV 80

Pseudoazurin (Paz) is a type I blue copper electron-transfer protein; Pseudoazurin (PAz) has been identified as an electron donor to the denitrification pathway. For example, PAz acts as an electron donor to cytochrome c peroxidase and N2OR from Paracoccus pantotrophus (Pp), and to the copper containing nitrite reductase (NiR) that catalyzes the second step of denitrification. It has been shown that pseudoazurin dramatically enhances the reaction profile of nitrite reduction by Paracoccus pantotrophus cytochrome cd1 and facilitates release of the product nitric oxide. The ability of this small redox protein to interact with a multitude of structurally different partners has been attributed to the hydrophobic character of the binding surface.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1965327819  70 EVLLGGDDGSLAFIPREFSVSSGEKIVFKNNAGfPHNVVFDEDEVPSGVDASKISMPEEdllnapgetYAVTLTEKGSYS 149
Cdd:cd04218     5 KMLNKGAGGAMVFEPAFLRAEPGDTVTFVPTDK-SHNAASIKGMLPEGAEPFKGKINEE---------ITVTFEKEGVYG 74

                          90
                  ....*....|....*..
gi 1965327819 150 FYCSPHQGAGMVGKVTV 166
Cdd:cd04218    75 YKCTPHYGMGMVGLIQV 91

Uncharacterized Cupredoxin-like subfamily; Cupredoxins contain type I copper centers and are involved in inter-molecular electron transfer reactions. Cupredoxins are blue copper proteins because they have an intense blue color due to the presence of a mononuclear type 1 (T1) copper site. Structurally, the cupredoxin-like fold consists of a beta-sandwich with 7 strands in 2 beta-sheets, which is arranged in a Greek-key beta-barrel. Some of these proteins have lost the ability to bind copper. Majority of family members contain multiple cupredoxin domain repeats; ceruloplasmin and coagulation factors V/VIII have six repeats; Laccase, ascorbate oxidase, and spore coat protein A, and multicopper oxidase CueO contain three repeats; and nitrite reductase has two repeats. Others are mono-domain cupredoxins, such as plastocyanin, pseudoazurin, plantacyanin, azurin, rusticyanin, stellacyanin, quinol oxidase and the periplasmic domain of cytochrome c oxidase subunit II.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1965327819  82 FIPREFSVSSGEKIVF--KNNAGFPHNVVFDEDEvpsGVDASK---ISMP--EEDLLN----APGETYAV--TLTEKGSY 148
Cdd:cd04211    14 FTPDSIQVKQGETVRFvvTNNGKIPHEFVIGTAA---ELKEHAemmRKHPgmEHDEPNmvslAPGKSGEIvwTFTKAGTF 90

                          90       100
                  ....*....|....*....|
gi 1965327819 149 SFYCS-P-HQGAGMVGKVTV 166
Cdd:cd04211    91 EFACLiPgHYEAGMVGKVTV 110