Characterization of PksD and PksG in Bacillus subtilis

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Sriparna Mukherjee (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/
Advisor
Jason Reddick

Abstract: Polyketides are a diverse class of natural products that have a wide variety of pharmacological applications. Polyketides are biosynthesized by modular polyketide synthases in a very similar fashion to that of fatty acids. The distinct features of each module govern the degree of reduction in the two carbons added during polyketide synthesis. The highly modular constitution of polyketide synthases makes them adjustable to synthesize unnatural medicinally important polyketides. Difficidin, an antibiotic polyketide, isolated from Bacillus subtilis strain 39320 and 39374, contains an unusual subunit that can not be explained by literature precedent for understood polyketide synthesis. Polyketide synthases have been proposed to biosynthesize difficidin. PksD, being homologous to acyltransferases, is expected to load malonyl CoA to the acyl carrier protein domains found in PksJLMNR, and AcpK. PksG is homologous to hydroxymethylglutaryl-CoA synthases and expected to be involved in the synthesis of the unusual subunit in difficidin. PksD, from B. subtilis strain 168, was successfully cloned, overexpressed, and purified. Attempts to characterize pure PksD by MALDI-MS were not successful. PksG was successfully cloned from B. subtilis strain 39374. Attempts at generating a knockout mutant of pksG in B. subtilis 39374 were not successful. The function of PksG in difficidin production could not be confirmed. However, on the basis of sequence data, we discovered that B. subtilis strain 39374 is likely B. amyloliquefaciens."--Abstract from author supplied metadata.

Additional Information

Publication
Thesis
Language: English
Date: 2006
Keywords
Polyketides, pharmacological applications
Subjects
Bacillus subtilis
Polyketides

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