Thymidylate synthase and pyrimidine hydroxymethylase: Thymidylate synthase (TS) and ...
155-268
1.51e-40
Thymidylate synthase and pyrimidine hydroxymethylase: Thymidylate synthase (TS) and deoxycytidylate hydroxymethylase (dCMP-HMase) are homologs that catalyze analogous alkylation of C5 of pyrimidine nucleotides. Both enzymes are involved in the biosynthesis of DNA precursors and are active as homodimers. However, they exhibit distinct pyrimidine base specificities and differ in the details of their catalyzed reactions. TS is biologically ubiquitous and catalyzes the conversion of dUMP and methylene-tetrahydrofolate (CH2THF) to dTMP and dihydrofolate (DHF). It also acts as a regulator of its own expression by binding and inactivating its own RNA. Due to its key role in the de novo pathway for thymidylate synthesis and, hence, DNA synthesis, it is one of the most conserved enzymes across species and phyla. TS is a well-recognized target for anticancer chemotherapy, as well as a valuable new target against infectious diseases. Interestingly, in several protozoa, a single polypeptide chain codes for both, dihydrofolate reductase (DHFR) and thymidylate synthase (TS), forming a bifunctional enzyme (DHFR-TS), possibly through gene fusion at a single evolutionary point. DHFR-TS is also active as a dimer. Virus encoded dCMP-HMase catalyzes the reversible conversion of dCMP and CH2THF to hydroxymethyl-dCMP and THF. This family also includes dUMP hydroxymethylase, which is encoded by several bacteriophages that infect Bacillus subtilis, for their own protection against the host restriction system, and contain hydroxymethyl-dUMP instead of dTMP in their DNA.
Pssm-ID: 238211 Cd Length: 215 Bit Score: 139.33 E-value: 1.51e-40
thymidylate synthase; Members of this protein family are thymidylate synthase, an enzyme that ...
155-268
4.20e-35
thymidylate synthase; Members of this protein family are thymidylate synthase, an enzyme that produces dTMP from dUMP. In prokaryotes, its gene usually is found close to that for dihydrofolate reductase, and in some systems the two enzymes are found as a fusion protein. This model excludes a set of related proteins (TIGR03283) that appears to replace this family in archaeal methanogens, where tetrahydrofolate is replaced by tetrahydromethanopterin. [Purines, pyrimidines, nucleosides, and nucleotides, 2'-Deoxyribonucleotide metabolism]
Pssm-ID: 213790 [Multi-domain] Cd Length: 295 Bit Score: 127.56 E-value: 4.20e-35
Thymidylate synthase and pyrimidine hydroxymethylase: Thymidylate synthase (TS) and ...
155-268
1.51e-40
Thymidylate synthase and pyrimidine hydroxymethylase: Thymidylate synthase (TS) and deoxycytidylate hydroxymethylase (dCMP-HMase) are homologs that catalyze analogous alkylation of C5 of pyrimidine nucleotides. Both enzymes are involved in the biosynthesis of DNA precursors and are active as homodimers. However, they exhibit distinct pyrimidine base specificities and differ in the details of their catalyzed reactions. TS is biologically ubiquitous and catalyzes the conversion of dUMP and methylene-tetrahydrofolate (CH2THF) to dTMP and dihydrofolate (DHF). It also acts as a regulator of its own expression by binding and inactivating its own RNA. Due to its key role in the de novo pathway for thymidylate synthesis and, hence, DNA synthesis, it is one of the most conserved enzymes across species and phyla. TS is a well-recognized target for anticancer chemotherapy, as well as a valuable new target against infectious diseases. Interestingly, in several protozoa, a single polypeptide chain codes for both, dihydrofolate reductase (DHFR) and thymidylate synthase (TS), forming a bifunctional enzyme (DHFR-TS), possibly through gene fusion at a single evolutionary point. DHFR-TS is also active as a dimer. Virus encoded dCMP-HMase catalyzes the reversible conversion of dCMP and CH2THF to hydroxymethyl-dCMP and THF. This family also includes dUMP hydroxymethylase, which is encoded by several bacteriophages that infect Bacillus subtilis, for their own protection against the host restriction system, and contain hydroxymethyl-dUMP instead of dTMP in their DNA.
Pssm-ID: 238211 Cd Length: 215 Bit Score: 139.33 E-value: 1.51e-40
thymidylate synthase; Members of this protein family are thymidylate synthase, an enzyme that ...
155-268
4.20e-35
thymidylate synthase; Members of this protein family are thymidylate synthase, an enzyme that produces dTMP from dUMP. In prokaryotes, its gene usually is found close to that for dihydrofolate reductase, and in some systems the two enzymes are found as a fusion protein. This model excludes a set of related proteins (TIGR03283) that appears to replace this family in archaeal methanogens, where tetrahydrofolate is replaced by tetrahydromethanopterin. [Purines, pyrimidines, nucleosides, and nucleotides, 2'-Deoxyribonucleotide metabolism]
Pssm-ID: 213790 [Multi-domain] Cd Length: 295 Bit Score: 127.56 E-value: 4.20e-35
Dihydrofolate reductase (DHFR). Reduces 7,8-dihydrofolate to 5,6,7,8-tetrahydrofolate with ...
1-134
3.28e-30
Dihydrofolate reductase (DHFR). Reduces 7,8-dihydrofolate to 5,6,7,8-tetrahydrofolate with NADPH as a cofactor. This is an essential step in the biosynthesis of deoxythymidine phosphate since 5,6,7,8-tetrahydrofolate is required to regenerate 5,10-methylenetetrahydrofolate which is then utilized by thymidylate synthase. Inhibition of DHFR interrupts thymidilate synthesis and DNA replication, inhibitors of DHFR (such as Methotrexate) are used in cancer chemotherapy. 5,6,7,8-tetrahydrofolate also is involved in glycine, serine, and threonine metabolism and aminoacyl-tRNA biosynthesis.
Pssm-ID: 238127 [Multi-domain] Cd Length: 158 Bit Score: 110.69 E-value: 3.28e-30
Database: CDSEARCH/cdd Low complexity filter: no Composition Based Adjustment: yes E-value threshold: 0.01
References:
Wang J et al. (2023), "The conserved domain database in 2023", Nucleic Acids Res.51(D)384-8.
Lu S et al. (2020), "The conserved domain database in 2020", Nucleic Acids Res.48(D)265-8.
Marchler-Bauer A et al. (2017), "CDD/SPARCLE: functional classification of proteins via subfamily domain architectures.", Nucleic Acids Res.45(D)200-3.
of the residues that compose this conserved feature have been mapped to the query sequence.
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Functional characterization of the conserved domain architecture found on the query.
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This image shows a graphical summary of conserved domains identified on the query sequence.
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if a domain or superfamily has been annotated with functional sites (conserved features),
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click on the bars or triangles to view your query sequence embedded in a multiple sequence alignment of the proteins used to develop the corresponding domain model.
The table lists conserved domains identified on the query sequence. Click on the plus sign (+) on the left to display full descriptions, alignments, and scores.
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To view your query sequence embedded in that multiple sequence alignment, click on the colored bars in the Graphical Summary portion of the search results page,
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Concise Display shows only the best scoring domain model, in each hit category listed below except non-specific hits, for each region on the query sequence.
(labeled illustration) Standard Display shows only the best scoring domain model from each source, in each hit category listed below for each region on the query sequence.
(labeled illustration) Full Display shows all domain models, in each hit category below, that meet or exceed the RPS-BLAST threshold for statistical significance.
(labeled illustration) Four types of hits can be shown, as available,
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specific hits meet or exceed a domain-specific e-value threshold
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and represent a very high confidence that the query sequence belongs to the same protein family as the sequences use to create the domain model
non-specific hits
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the domain superfamily to which the specific and non-specific hits belong
multi-domain models that were computationally detected and are likely to contain multiple single domains
Retrieve proteins that contain one or more of the domains present in the query sequence, using the Conserved Domain Architecture Retrieval Tool
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