1b5e
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Bacteriophage T4 deoxycytidylate hydroxymethylase (EC 2.1.2.8), a | + | Bacteriophage T4 deoxycytidylate hydroxymethylase (EC 2.1.2.8), a homodimer of 246-residue subunits, catalyzes hydroxymethylation of the cytosine base in deoxycytidylate (dCMP) to produce 5-hydroxymethyl-dCMP. It forms part of a phage DNA protection system and appears to function in vivo as a component of a multienzyme complex called deoxyribonucleoside triphosphate (dNTP) synthetase. We have determined its crystal structure in the presence of the substrate dCMP at 1.6 A resolution. The structure reveals a subunit fold and a dimerization pattern in common with thymidylate synthases, despite low (approximately 20%) sequence identity. Among the residues that form the dCMP binding site, those interacting with the sugar and phosphate are arranged in a configuration similar to the deoxyuridylate binding site of thymidylate synthases. However, the residues interacting directly or indirectly with the cytosine base show a more divergent structure and the presumed folate cofactor binding site is more open. Our structure reveals a water molecule properly positioned near C-6 of cytosine to add to the C-7 methylene intermediate during the last step of hydroxymethylation. On the basis of sequence comparison and crystal packing analysis, a hypothetical model for the interaction between T4 deoxycytidylate hydroxymethylase and T4 thymidylate synthase in the dNTP-synthesizing complex has been built. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Enterobacteria phage t2]] | [[Category: Enterobacteria phage t2]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Sohn, S | + | [[Category: Sohn, S H.]] |
| - | [[Category: Song, H | + | [[Category: Song, H K.]] |
| - | [[Category: Suh, S | + | [[Category: Suh, S W.]] |
[[Category: DCM]] | [[Category: DCM]] | ||
[[Category: dntp synthesizing complex]] | [[Category: dntp synthesizing complex]] | ||
[[Category: hydroxymethylase]] | [[Category: hydroxymethylase]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:51:46 2008'' |
Revision as of 09:51, 21 February 2008
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DCMP HYDROXYMETHYLASE FROM T4
Overview
Bacteriophage T4 deoxycytidylate hydroxymethylase (EC 2.1.2.8), a homodimer of 246-residue subunits, catalyzes hydroxymethylation of the cytosine base in deoxycytidylate (dCMP) to produce 5-hydroxymethyl-dCMP. It forms part of a phage DNA protection system and appears to function in vivo as a component of a multienzyme complex called deoxyribonucleoside triphosphate (dNTP) synthetase. We have determined its crystal structure in the presence of the substrate dCMP at 1.6 A resolution. The structure reveals a subunit fold and a dimerization pattern in common with thymidylate synthases, despite low (approximately 20%) sequence identity. Among the residues that form the dCMP binding site, those interacting with the sugar and phosphate are arranged in a configuration similar to the deoxyuridylate binding site of thymidylate synthases. However, the residues interacting directly or indirectly with the cytosine base show a more divergent structure and the presumed folate cofactor binding site is more open. Our structure reveals a water molecule properly positioned near C-6 of cytosine to add to the C-7 methylene intermediate during the last step of hydroxymethylation. On the basis of sequence comparison and crystal packing analysis, a hypothetical model for the interaction between T4 deoxycytidylate hydroxymethylase and T4 thymidylate synthase in the dNTP-synthesizing complex has been built.
About this Structure
1B5E is a Single protein structure of sequence from Enterobacteria phage t2 with as ligand. Active as Deoxycytidylate 5-hydroxymethyltransferase, with EC number 2.1.2.8 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Crystal structure of deoxycytidylate hydroxymethylase from bacteriophage T4, a component of the deoxyribonucleoside triphosphate-synthesizing complex., Song HK, Sohn SH, Suh SW, EMBO J. 1999 Mar 1;18(5):1104-13. PMID:10064578
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