1jcl

Publication Abstract from PubMed

In classical enzymology, intermediates and transition states in a catalytic mechanism are usually inferred from a series of biochemical experiments. Here, we derive an enzyme mechanism from true atomic-resolution x-ray structures of reaction intermediates. Two ultra-high resolution structures of wild-type and mutant d-2-deoxyribose-5-phosphate (DRP) aldolase complexes with DRP at 1.05 and 1.10 angstroms unambiguously identify the postulated covalent carbinolamine and Schiff base intermediates in the aldolase mechanism. In combination with site-directed mutagenesis and (1)H nuclear magnetic resonance, we can now propose how the heretofore elusive C-2 proton abstraction step and the overall stereochemical course are accomplished. A proton relay system appears to activate a conserved active-site water that functions as the critical mediator for proton transfer.

Observation of covalent intermediates in an enzyme mechanism at atomic resolution.,Heine A, DeSantis G, Luz JG, Mitchell M, Wong CH, Wilson IA Science. 2001 Oct 12;294(5541):369-74. PMID:11598300^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.