This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1jc4
From Proteopedia
OCA (Talk | contribs)
(New page: 200px<br /><applet load="1jc4" size="450" color="white" frame="true" align="right" spinBox="true" caption="1jc4, resolution 2.00Å" /> '''Crystal Structure of...)
Next diff →
Revision as of 21:18, 24 November 2007
|
Crystal Structure of Se-Met Methylmalonyl-CoA Epimerase
Overview
BACKGROUND: Methylmalonyl-CoA epimerase (MMCE) is an essential enzyme in, the breakdown of odd-numbered fatty acids and of the amino acids valine, isoleucine, and methionine. Present in many bacteria and in animals, it, catalyzes the conversion of (2R)-methylmalonyl-CoA to, (2S)-methylmalonyl-CoA, the substrate for the B12-dependent enzyme, methylmalonyl-CoA mutase. Defects in this pathway can result in severe, acidosis and cause damage to the central nervous system in humans., RESULTS: The crystal structure of MMCE from Propionibacterium shermanii, has been determined at 2.0 A resolution. The MMCE monomer is folded into, two tandem betaalphabetabetabeta modules that pack edge-to-edge to, generate an 8-stranded beta sheet. Two monomers then pack back-to-back to, create a tightly associated dimer. In each monomer, the beta sheet curves, around to create a deep cleft, in the floor of which His12, Gln65, His91, and Glu141 provide a binding site for a divalent metal ion, as shown by, the binding of Co2+. Modeling 2-methylmalonate into the active site, identifies two glutamate residues as the likely essential bases for the, epimerization reaction. CONCLUSIONS: The betaalphabetabetabeta modules of, MMCE correspond with those found in several other proteins, including, bleomycin resistance protein, glyoxalase I, and a family of extradiol, dioxygenases. Differences in connectivity are consistent with the, evolution of these very different proteins from a common precursor by, mechanisms of gene duplication and domain swapping. The metal binding, residues also align precisely, and striking structural similarities, between MMCE and glyoxalase I suggest common mechanisms in their, respective epimerization and isomerization reactions.
About this Structure
1JC4 is a Single protein structure of sequence from Propionibacterium freudenreichii subsp. shermanii with SO4 as ligand. Active as Methylmalonyl-CoA epimerase, with EC number 5.1.99.1 Full crystallographic information is available from OCA.
Reference
Crystal structure of methylmalonyl-coenzyme A epimerase from P. shermanii: a novel enzymatic function on an ancient metal binding scaffold., McCarthy AA, Baker HM, Shewry SC, Patchett ML, Baker EN, Structure. 2001 Jul 3;9(7):637-46. PMID:11470438
Page seeded by OCA on Sat Nov 24 23:26:08 2007
