1jcl
OBSERVATION OF COVALENT INTERMEDIATES IN AN ENZYME MECHANISM AT ATOMIC RESOLUTION
|
OverviewOverview
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.
About this StructureAbout this Structure
1JCL is a Single protein structure of sequence from Escherichia coli with as ligand. Active as Deoxyribose-phosphate aldolase, with EC number 4.1.2.4 Full crystallographic information is available from OCA.
ReferenceReference
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
Page seeded by OCA on Thu Feb 21 13:21:06 2008