1gpu
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TRANSKETOLASE COMPLEX WITH REACTION INTERMEDIATE
OverviewOverview
Kinetic and spectroscopic data indicated that addition of the donor, substrate hydroxypyruvate to the thiamin diphosphate (ThDP)-dependent, enzyme transketolase (TK) led to the accumulation of the, alpha-carbanion/enamine of (alpha,beta-dihydroxyethyl) ThDP, the key, reaction intermediate in enzymatic thiamin catalysis. The, three-dimensional structure of this intermediate trapped in the active, site of yeast TK was determined to 1.9-A resolution by using, cryocrystallography. The electron density suggests a planar, alpha-carbanion/enamine intermediate having the E-configuration. The, reaction intermediate is firmly held in place through direct hydrogen, bonds to His-103 and His-481 and an indirect hydrogen bond via a water, molecule to His-69. The 4-NH(2) group of the amino-pyrimidine ... [(full description)]
About this StructureAbout this Structure
1GPU is a [Single protein] structure of sequence from [Saccharomyces cerevisiae] with CA and THD as [ligands]. Active as [Transketolase], with EC number [2.2.1.1]. Structure known Active Site: AC1. Full crystallographic information is available from [OCA].
ReferenceReference
Snapshot of a key intermediate in enzymatic thiamin catalysis: crystal structure of the alpha-carbanion of (alpha,beta-dihydroxyethyl)-thiamin diphosphate in the active site of transketolase from Saccharomyces cerevisiae., Fiedler E, Thorell S, Sandalova T, Golbik R, Konig S, Schneider G, Proc Natl Acad Sci U S A. 2002 Jan 22;99(2):591-5. Epub 2002 Jan 2. PMID:11773632
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