Details

Autor(en) / Beteiligte

• Jonsson, Stefan
• Ricagno, Stefano
• Lindqvist, Ylva
• Richards, Nigel G J

Titel

Kinetic and Mechanistic Characterization of the Formyl-CoA Transferase from Oxalobacter formigenes

Ist Teil von

• The Journal of biological chemistry, 2004-08, Vol.279 (34), p.36003-36012

Ort / Verlag

United States: American Society for Biochemistry and Molecular Biology

Erscheinungsjahr

2004

Link zum Volltext

Quelle

Electronic Journals Library

Beschreibungen/Notizen

• Oxalobacter formigenes is an obligate anaerobe that colonizes the human gastrointestinal tract and employs oxalate breakdown to generate ATP in a novel process involving the interplay of two coupled enzymes and a membrane-bound oxalate:formate antiporter. Formyl-CoA transferase is a critical enzyme in oxalate-dependent ATP synthesis and is the first Class III CoA-transferase for which a high resolution, three-dimensional structure has been determined (Ricagno, S., Jonsson, S., Richards, N., and Lindqvist, Y. (2003) EMBO J. 22, 3210–3219). We now report the first detailed kinetic characterizations of recombinant, wild type formyl-CoA transferase and a number of site-specific mutants, which suggest that catalysis proceeds via a series of anhydride intermediates. Further evidence for this mechanistic proposal is provided by the x-ray crystallographic observation of an acylenzyme intermediate that is formed when formyl-CoA transferase is incubated with oxalyl-CoA. The catalytic mechanism of formyl-CoA transferase is therefore established and is almost certainly employed by all other members of the Class III CoA-transferase family.