Publication Date:
2012-03-03
Description:
The sulfonamide antibiotics inhibit dihydropteroate synthase (DHPS), a key enzyme in the folate pathway of bacteria and primitive eukaryotes. However, resistance mutations have severely compromised the usefulness of these drugs. We report structural, computational, and mutagenesis studies on the catalytic and resistance mechanisms of DHPS. By performing the enzyme-catalyzed reaction in crystalline DHPS, we have structurally characterized key intermediates along the reaction pathway. Results support an S(N)1 reaction mechanism via formation of a novel cationic pterin intermediate. We also show that two conserved loops generate a substructure during catalysis that creates a specific binding pocket for p-aminobenzoic acid, one of the two DHPS substrates. This substructure, together with the pterin-binding pocket, explains the roles of the conserved active-site residues and reveals how sulfonamide resistance arises.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3531234/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3531234/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yun, Mi-Kyung -- Wu, Yinan -- Li, Zhenmei -- Zhao, Ying -- Waddell, M Brett -- Ferreira, Antonio M -- Lee, Richard E -- Bashford, Donald -- White, Stephen W -- AI070721/AI/NIAID NIH HHS/ -- CA21765/CA/NCI NIH HHS/ -- P30 CA021765/CA/NCI NIH HHS/ -- R01 AI070721/AI/NIAID NIH HHS/ -- New York, N.Y. -- Science. 2012 Mar 2;335(6072):1110-4. doi: 10.1126/science.1214641.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22383850" target="_blank"〉PubMed〈/a〉
Keywords:
4-Aminobenzoic Acid/chemistry/metabolism
;
Amino Acid Sequence
;
Anti-Bacterial Agents/chemistry/metabolism/*pharmacology
;
Bacillus anthracis/drug effects/enzymology
;
Biocatalysis
;
Catalytic Domain
;
Crystallization
;
Crystallography, X-Ray
;
Dihydropteroate Synthase/*chemistry/genetics/*metabolism
;
Diphosphates/chemistry/metabolism
;
*Drug Resistance, Bacterial
;
Magnesium/chemistry
;
Models, Chemical
;
Models, Molecular
;
Molecular Sequence Data
;
Mutagenesis
;
Parabens/chemistry/metabolism
;
Protein Conformation
;
Sulfamethoxazole/chemistry/metabolism/*pharmacology
;
Sulfathiazoles/chemistry/metabolism/*pharmacology
;
Yersinia pestis/drug effects/enzymology
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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