In:
Applied and Environmental Microbiology, American Society for Microbiology, Vol. 74, No. 23 ( 2008-12), p. 7235-7242
Abstract:
Gene fscTE , encoding a putative type II thioesterase (TEII), was associated with the FR-008/candicidin gene cluster. Deletion of fscTE reduced approximately 90% of the FR-008/candicidin production, while the production level was well restored when fscTE was added back to the mutant in trans . FscTE was unable to compensate for the release of the maturely elongated polyketide as site-directed inactivation of the type I thioesterase (TEI) totally abolished FR-008/candicidin production. Direct biochemical analysis of FscTE in parallel with its homologue TylO from the tylosin biosynthetic pathway demonstrated their remarkable preferences for acyl-thioesters (i.e., propionyl- S - N -acetylcysteamine [SNAC] over methylmalonyl-SNAC and acetyl-SNAC over malonyl-SNAC) and thus concluded that TEII could maintain effective polyketide biosynthesis by selectively removing the nonelongatable residues bound to acyl carrier proteins. Overexpression of FscTE under the strong constitutive ermE * p promoter in the wild-type strain did not suppress FR-008/candicidin formation, which confirmed its substrate specificity in vivo. Furthermore, successful complementation of the fscTE mutant was obtained with fscTE and tylO , whereas no complementation was detected with nonribosomal peptide synthetase (NRPS) TEII tycF and srfAD , reflecting substrate specificities of TEIIs distinctive from those of either polyketide synthases or NRPSs.
Type of Medium:
Online Resource
ISSN:
0099-2240
,
1098-5336
DOI:
10.1128/AEM.01012-08
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2008
detail.hit.zdb_id:
223011-2
detail.hit.zdb_id:
1478346-0
SSG:
12
