1seh: Difference between revisions

[[Image:1seh.gif|left|200px]]<br /><applet load="1seh" size="350" color="white" frame="true" align="right" spinBox="true"  

dUTPase is essential to keep uracil out of DNA. Crystal structures of substrate (dUTP and alpha,beta-imino-dUTP) and product complexes of wild type and mutant dUTPases were determined to reveal how an enzyme responsible for DNA integrity functions. A kinetic analysis of wild type and mutant dUTPases was performed to obtain relevant mechanistic information in solution. Substrate hydrolysis is shown to be initiated via in-line nucleophile attack of a water molecule oriented by an activating conserved aspartate residue. Substrate binding in a catalytically competent conformation is achieved by (i) multiple interactions of the triphosphate moiety with catalysis-assisting Mg2+, (ii) a concerted motion of residues from three conserved enzyme motifs as compared with the apoenzyme, and (iii) an intricate hydrogen-bonding network that includes several water molecules in the active site. Results provide an understanding for the catalytic role of conserved residues in dUTPases.

1SEH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=UMP:'>UMP</scene> and <scene name='pdbligand=TRS:'>TRS</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/dUTP_diphosphatase dUTP diphosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.6.1.23 3.6.1.23] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SEH OCA].  

[[Category: Vertessy, B G.]]

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