Document Detail


Biochemical and structural characterization of germicidin synthase: analysis of a type III polyketide synthase that employs acyl-ACP as a starter unit donor.
MedLine Citation:
PMID:  22480290     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Germicidin synthase (Gcs) from Streptomyces coelicolor is a type III polyketide synthase (PKS) with broad substrate flexibility for acyl groups linked through a thioester bond to either coenzyme A (CoA) or acyl carrier protein (ACP). Germicidin synthesis was reconstituted in vitro by coupling Gcs with fatty acid biosynthesis. Since Gcs has broad substrate flexibility, we directly compared the kinetic properties of Gcs with both acyl-ACP and acyl-CoA. The catalytic efficiency of Gcs for acyl-ACP was 10-fold higher than for acyl-CoA, suggesting a strong preference toward carrier protein starter unit transfer. The 2.9 Å germicidin synthase crystal structure revealed canonical type III PKS architecture along with an unusual helical bundle of unknown function that appears to extend the dimerization interface. A pair of arginine residues adjacent to the active site affect catalytic activity but not ACP binding. This investigation provides new and surprising information about the interactions between type III PKSs and ACPs that will facilitate the construction of engineered systems for production of novel polyketides.
Authors:
Joseph A Chemler; Tonia J Buchholz; Todd W Geders; David L Akey; Christopher M Rath; George E Chlipala; Janet L Smith; David H Sherman
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2012-04-23
Journal Detail:
Title:  Journal of the American Chemical Society     Volume:  134     ISSN:  1520-5126     ISO Abbreviation:  J. Am. Chem. Soc.     Publication Date:  2012 May 
Date Detail:
Created Date:  2012-05-02     Completed Date:  2012-08-24     Revised Date:  2013-05-06    
Medline Journal Info:
Nlm Unique ID:  7503056     Medline TA:  J Am Chem Soc     Country:  United States    
Other Details:
Languages:  eng     Pagination:  7359-66     Citation Subset:  IM    
Copyright Information:
© 2012 American Chemical Society
Affiliation:
Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, USA.
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MeSH Terms
Descriptor/Qualifier:
Acyl Carrier Protein / metabolism*
Acyl Coenzyme A / metabolism
Bacterial Proteins / chemistry,  genetics,  metabolism*
Crystallography, X-Ray
Models, Molecular
Mutation
Polyketide Synthases / chemistry,  genetics,  metabolism*
Protein Binding
Pyrones / metabolism*
Signal Transduction
Streptomyces coelicolor / chemistry,  enzymology*,  genetics
Substrate Specificity
Grant Support
ID/Acronym/Agency:
DK42303/DK/NIDDK NIH HHS; GM076477/GM/NIGMS NIH HHS; GM095065/GM/NIGMS NIH HHS; R01 DK042303/DK/NIDDK NIH HHS; R01 GM076477/GM/NIGMS NIH HHS; R01 GM076477-07/GM/NIGMS NIH HHS
Chemical
Reg. No./Substance:
0/Acyl Carrier Protein; 0/Acyl Coenzyme A; 0/Bacterial Proteins; 0/Pyrones; 151271-57-7/germicidin; 79956-01-7/Polyketide Synthases

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


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