Download MendeleyObservation of covalent intermediates in an enzyme mechanism at atomic resolution.
Heine, A., DeSantis, G., Luz, J.G., Mitchell, M., Wong, C.H., Wilson, I.A.(2001) Science 294: 369-374
- PubMed: 11598300
- DOI: https://doi.org/10.1126/science.1063601
- Primary Citation of Related Structures:
1JCJ, 1JCL - PubMed Abstract:
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.
Organizational Affiliation:
Department of Molecular Biology, Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
