2pyu: Difference between revisions

From Proteopedia
Jump to navigationJump to search
OCA (talk | contribs)
No edit summary
OCA (talk | contribs)
No edit summary
Line 1: Line 1:
[[Image:2pyu.jpg|left|200px]]
{{Seed}}
[[Image:2pyu.png|left|200px]]


<!--
<!--
Line 9: Line 10:
{{STRUCTURE_2pyu|  PDB=2pyu  |  SCENE=  }}  
{{STRUCTURE_2pyu|  PDB=2pyu  |  SCENE=  }}  


'''Structure of the E. coli inosine triphosphate pyrophosphatase RgdB in complex with IMP'''
===Structure of the E. coli inosine triphosphate pyrophosphatase RgdB in complex with IMP===




==Overview==
<!--
Inosine triphosphate pyrophosphatases, which are ubiquitous house-cleaning enzymes, hydrolyze noncanonical nucleoside triphosphates (inosine triphosphate (ITP) and xanthosine triphosphate (XTP)) and prevent the incorporation of hypoxanthine or xanthine into nascent DNA or RNA. Here we present the 1.5-A-resolution crystal structure of the inosine triphosphate pyrophosphatase RdgB from Escherichia coli in a free state and in complex with a substrate (ITP+Ca(2+)) or a product (inosine monophosphate (IMP)). ITP binding to RdgB induced a large displacement of the alpha1 helix, closing the enzyme active site. This positions the conserved Lys13 close to the bridging oxygen between the alpha- and beta-phosphates of the substrate, weakening the P(alpha)-O bond. On the other side of the substrate, the conserved Asp69 is proposed to act as a base coordinating the catalytic water molecule. Our data provide insight into the molecular mechanisms of the substrate selectivity and catalysis of RdgB and other ITPases.
The line below this paragraph, {{ABSTRACT_PUBMED_17976651}}, adds the Publication Abstract to the page
(as it appears on PubMed at http://www.pubmed.gov), where 17976651 is the PubMed ID number.
-->
{{ABSTRACT_PUBMED_17976651}}


==About this Structure==
==About this Structure==
Line 30: Line 34:
[[Category: Hydrolase]]
[[Category: Hydrolase]]
[[Category: Itp pyrophosphatase x-ray structure enzyme mechanism product]]
[[Category: Itp pyrophosphatase x-ray structure enzyme mechanism product]]
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May  4 14:02:15 2008''
 
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 29 14:49:49 2008''