We report the crystal structure of E. coli ketopantoate hydroxymethyltransferase (KPHMT) at 1.9 A resolution, in complex with its product, ketopantoate. KPHMT catalyzes the first step in the biosynthesis of pantothenate (vitamin B(5)), the precursor of coenzyme A and the acyl carrier protein cofactor ...
We report the crystal structure of E. coli ketopantoate hydroxymethyltransferase (KPHMT) at 1.9 A resolution, in complex with its product, ketopantoate. KPHMT catalyzes the first step in the biosynthesis of pantothenate (vitamin B(5)), the precursor of coenzyme A and the acyl carrier protein cofactor. The structure of the decameric enzyme was solved by multiwavelength anomalous dispersion to locate 160 selenomethionine sites and phase 560 kDa of protein, making it the largest structure solved by this approach. KPHMT adopts the (betaalpha)(8) barrel fold and is a member of the phosphoenolpyruvate/pyruvate superfamily. The active site contains a ketopantoate bidentately coordinated to Mg(2+). Similar binding is likely for the substrate, alpha-ketoisovalerate, orienting the C3 for deprotonation.
Related Citations:
Ketopantoate Hydroxymethyltransferase. I. Purification and Role in Pantothenate Biosynthesis. Teller, J.H., Powers, S.G., Snell, E.E. (1976) J Biol Chem 251: 3780
Ketopantoate Hydroxymethyltransferase. II. Physical, Catalytic, and Regulatory Properties. Powers, S.G., Snell, E.E. (1976) J Biol Chem 251: 3786
Cloning and Sequencing of the Escherichia coli panB gene, which encodes ketopantoate hydroxymethyltransferase, and overexpression of the enzyme. Jones, C.E., Brook, J.M., Buck, D., Abell, C., Smith, A.G. (1993) J Bacteriol 175: 2125
Organizational Affiliation:
Department of Biochemistry, 80 Tennis Court Road, Cambridge CB2 1GA, United Kingdom.
Download Mendeley
