|
|
| Line 1: |
Line 1: |
| [[Image:1jc4.jpg|left|200px]] | | {{Seed}} |
| | [[Image:1jc4.png|left|200px]] |
|
| |
|
| <!-- | | <!-- |
| Line 9: |
Line 10: |
| {{STRUCTURE_1jc4| PDB=1jc4 | SCENE= }} | | {{STRUCTURE_1jc4| PDB=1jc4 | SCENE= }} |
|
| |
|
| '''Crystal Structure of Se-Met Methylmalonyl-CoA Epimerase'''
| | ===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.
| | The line below this paragraph, {{ABSTRACT_PUBMED_11470438}}, adds the Publication Abstract to the page |
| | (as it appears on PubMed at http://www.pubmed.gov), where 11470438 is the PubMed ID number. |
| | --> |
| | {{ABSTRACT_PUBMED_11470438}} |
|
| |
|
| ==About this Structure== | | ==About this Structure== |
| Line 30: |
Line 34: |
| [[Category: Methylmalonyl-coa]] | | [[Category: Methylmalonyl-coa]] |
| [[Category: Vicinal oxygen chelate superfamily]] | | [[Category: Vicinal oxygen chelate superfamily]] |
| ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 21:02:29 2008'' | | |
| | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 1 20:00:19 2008'' |
