1RQE

Propionibacterium shermanii transcarboxylase 5S subunit bound to oxaloacetate

Summary for 1RQE

• Entry DOI: 10.2210/pdb1rqe/pdb
• Related: 1RQB 1RQH 1RR2 1S27 1S3H
• Descriptor: transcarboxylase 5S subunit, OXALOACETATE ION, COBALT (II) ION, ... (4 entities in total)
• Functional Keywords: tim-barrel, carbamylated lysine, transcarboxylase, cobalt, oxaloacetate, transferase
• Biological source: Propionibacterium freudenreichii subsp. shermanii
• Total number of polymer chains: 1
• Total formula weight: 59799.46

Authors

Hall, P.R.,Zheng, R.,Antony, L.,Pusztai-Carey, M.,Carey, P.R.,Yee, V.C. (deposition date: 2003-12-05, release date: 2004-09-07, Last modification date: 2023-08-23)

Primary citation

Hall, P.R.,Zheng, R.,Antony, L.,Pusztai-Carey, M.,Carey, P.R.,Yee, V.C.
Transcarboxylase 5S structures: assembly and catalytic mechanism of a multienzyme complex subunit.
Embo J., 23:3621-3631, 2004

PubMed Abstract: 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.

PubMed: 15329673
DOI: 10.1038/sj.emboj.7600373

Experimental method

X-RAY DIFFRACTION (2.5 Å)