1km2: Difference between revisions

Revision as of 22:54, 2 May 2008

crystal structure of orotidine monophosphate mutant Q185A with 6-azaUMP

OverviewOverview

The crystal structures of orotidine 5'-monophosphate decarboxylases from four different sources have been published recently. However, the detailed mechanism of catalysis of the most proficient enzyme known to date remains elusive. As the ligand-protein interactions at the orotate binding site are crucial to the understanding of this enzyme, we mutated several of the residues surrounding the aromatic part of the substrate, individually and in combination. The ensuing effects on enzyme structure and stability were characterized by X-ray crystallography of inhibitor, product, or substrate complexes and by chemical denaturation with guanidine hydrochloride, respectively. The results are consistent with the residues K42D70K72D75B being charged and forming an 'alternate charge network' around the reactive part of the substrate. In addition to exerting charge-charge repulsion on the orotate carboxylate, Asp70 also makes a crucial contribution to enzyme stability. Consequently, orotidine 5'-monophosphate decarboxylases seem to require the presence of a negative charge at this position for catalysis as well as for correct and stable folding.

About this StructureAbout this Structure

1KM2 is a Single protein structure of sequence from Methanothermobacter thermautotrophicus. Full crystallographic information is available from OCA.

ReferenceReference

Mapping the active site-ligand interactions of orotidine 5'-monophosphate decarboxylase by crystallography., Wu N, Gillon W, Pai EF, Biochemistry. 2002 Mar 26;41(12):4002-11. PMID:11900543 Page seeded by OCA on Fri May 2 22:54:16 2008

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OCA

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 [[Image:1km2.gif|left|200px]]
- {{Structure
+<!--
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+The line below this paragraph, containing "STRUCTURE_1km2", creates the "Structure Box" on the page.
-|SITE=
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=UP6:6-AZA+URIDINE+5&#39;-MONOPHOSPHATE'>UP6</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Orotidine-5'-phosphate_decarboxylase Orotidine-5'-phosphate decarboxylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.23 4.1.1.23] </span>
+or leave the SCENE parameter empty for the default display.
-|GENE=
+-->
-|DOMAIN=
+{{STRUCTURE_1km2|  PDB=1km2  |  SCENE=  }}
-|RELATEDENTRY=[[1kly|1KLY]], [[1klz|1KLZ]], [[1km0|1KM0]], [[1km1|1KM1]], [[1km3|1KM3]], [[1km4|1KM4]], [[1km5|1KM5]], [[1km6|1KM6]]
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1km2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1km2 OCA], [http://www.ebi.ac.uk/pdbsum/1km2 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1km2 RCSB]</span>
-}}
 '''crystal structure of orotidine monophosphate mutant Q185A with 6-azaUMP'''
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 [[Category: Pai, E F.]]
 [[Category: Wu, N.]]
-[[Category: tim barrel]]
+[[Category: Tim barrel]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May  2 22:54:16 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 21:50:26 2008''