Publication Date:
2001-10-13
Description:
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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Heine, A -- DeSantis, G -- Luz, J G -- Mitchell, M -- Wong, C H -- Wilson, I A -- GM44154/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2001 Oct 12;294(5541):369-74.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Biology, Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11598300" target="_blank"〉PubMed〈/a〉
Keywords:
Aldehyde-Lyases/*chemistry/genetics/*metabolism
;
Amino Acid Substitution
;
Binding Sites
;
Catalysis
;
Chemistry, Physical
;
Crystallization
;
Crystallography, X-Ray
;
Escherichia coli/enzymology
;
Hydrogen Bonding
;
Hydrogen-Ion Concentration
;
Ligands
;
Lysine/chemistry
;
Models, Chemical
;
Mutagenesis, Site-Directed
;
Mutation
;
Nuclear Magnetic Resonance, Biomolecular
;
Physicochemical Phenomena
;
Protein Conformation
;
Protein Folding
;
Protein Structure, Tertiary
;
Protons
;
Ribosemonophosphates/*chemistry/*metabolism
;
Schiff Bases
;
Water
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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