1RR2 image
Entry Detail
PDB ID:
1RR2
Keywords:
Title:
Propionibacterium shermanii transcarboxylase 5S subunit bound to 2-ketobutyric acid
Biological Source:
PDB Version:
Deposition Date:
2003-12-08
Release Date:
2004-09-07
Method Details:
Experimental Method:
Resolution:
2.00 Å
R-Value Free:
0.20
R-Value Work:
0.17
R-Value Observed:
0.17
Space Group:
C 2 2 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:transcarboxylase 5S subunit
Chain IDs:A
Chain Length:539
Number of Molecules:1
Biological Source:Propionibacterium freudenreichii subsp. shermanii
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
KCX A LYS LYSINE NZ-CARBOXYLIC ACID
Primary Citation
Transcarboxylase 5S structures: assembly and catalytic mechanism of a multienzyme complex subunit.
Embo J. 23 3621 3631 (2004)
PMID: 15329673 DOI: 10.1038/sj.emboj.7600373

Abstact

Transcarboxylase is a 1.2 million Dalton (Da) multienzyme complex from Propionibacterium shermanii that couples two carboxylation reactions, transferring CO(2)(-) from methylmalonyl-CoA to pyruvate to yield propionyl-CoA and oxaloacetate. Crystal structures of the 5S metalloenzyme subunit, which catalyzes the second carboxylation reaction, have been solved in free form and bound to its substrate pyruvate, product oxaloacetate, or inhibitor 2-ketobutyrate. The structure reveals a dimer of beta(8)alpha(8) barrels with an active site cobalt ion coordinated by a carbamylated lysine, except in the oxaloacetate complex in which the product's carboxylate group serves as a ligand instead. 5S and human pyruvate carboxylase (PC), an enzyme crucial to gluconeogenesis, catalyze similar reactions. A 5S-based homology model of the PC carboxyltransferase domain indicates a conserved mechanism and explains the molecular basis of mutations in lactic acidemia. PC disease mutations reproduced in 5S result in a similar decrease in carboxyltransferase activity and crystal structures with altered active sites.

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Primary Citation of related structures