3GK7

Crystal structure of 4-hydroxybutyrate CoA-Transferase from Clostridium aminobutyricum

Summary for 3GK7

• Entry DOI: 10.2210/pdb3gk7/pdb
• Related: 2OAS 3D3U
• Descriptor: 4-Hydroxybutyrate CoA-transferase, SPERMIDINE, 2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL, ... (4 entities in total)
• Functional Keywords: alpha/beta protein, transferase
• Biological source: Clostridium aminobutyricum
• Total number of polymer chains: 2
• Total formula weight: 98448.85

Authors

Messerschmidt, A.,Macieira, S.,Velarde, M. (deposition date: 2009-03-10, release date: 2009-12-22, Last modification date: 2023-11-01)

Primary citation

Macieira, S.,Zhang, J.,Velarde, M.,Buckel, W.,Messerschmidt, A.
Crystal structure of 4-hydroxybutyrate CoA-transferase from Clostridium aminobutyricum
Biol.Chem., 390:1251-1263, 2009

PubMed Abstract: 4-Hydroxybutyrate CoA-transferases (4-HB-CoAT) takes part in the fermentation of 4-aminobutyrate to ammonia, acetate, and butyrate in anaerobic bacteria such as Clostridium aminobutyricum and Porphyromonas gingivalis or facultative anaerobic bacteria such as Shewanella oneidensis. Site-directed mutagenesis of the highly active enzyme has identified the catalytic glutamate residue as E238. Crystal structure of this enzyme has been determined at a resolution of 1.85 A. The 438-amino acid residue polypeptide chain folds into two topologically similar domains with an open alpha/beta-fold, which is also found in other CoAT family I and family II members. The data indicate that the members of CoAT families I and II are closely related; the latter only lacking the catalytic glutamate residue. A putative co-substrate binding site for the 4-HB-CoAT was identified, in which a 4-hydroxybutyrate molecule has been modeled. This site is also responsible for binding the acetyl group of acetyl-CoA or the succinyl group of succinyl-CoA in succinyl-CoA:3-oxoacid CoA-transferase from mammalian mitochondria. Mutations of relevant active site amino acid residues have been produced and their activities tested to corroborate the proposed structural model for substrate binding. 4-HB-CoAT from C. aminobutyricum represents the only functionally characterized 4-HB-CoAT present in the structural database.

PubMed: 19804364
DOI: 10.1515/BC.2009.147

Experimental method

X-RAY DIFFRACTION (1.85 Å)