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B6db references: 26685675.a

type Journal Article
authors Bekeova C, Rehakova A, Feckova L, Vlckova S, Novakova R, Mingyar E, Kormanec J
title Characterisation of the genes involved in the biosynthesis and attachment of the aminodeoxysugar D-forosamine in the auricin gene cluster of Streptomyces aureofaciens CCM3239
journal Appl Microbiol Biotechnol
sel unselected
ui 26685675 a
year (2016)
volume 100
number 7
pages 3177-95
keywords Antibiotics; Auricin; D-Forosamine; Polyketide; Regulation; Secondary metabolite; Streptomyces
abstract We previously identified the aur1 gene cluster which produces the angucycline antibiotic auricin. Preliminary characterisation of auricin revealed that it is modified by a single aminodeoxysugar, D-forosamine. Here we characterise the D-forosamine-specific genes. The four close tandem genes, aur1TQSV, encoding enzymes involved in the initial steps of the deoxysugar biosynthesis, were located on a large operon with other core auricin biosynthetic genes. Deleting these genes resulted in the absence of auricin and the production of deglycosylated auricin intermediates. The two final D-forosamine biosynthetic genes, sa59, an NDP-hexose aminotransferase, and sa52, an NDP-aminohexose N-dimethyltransferase, are located in a region rather distant from the core auricin genes. A deletion analysis of these genes confirmed their role in D-forosamine biosynthesis. The Δsa59 mutant had a phenotype similar to that of the cluster deletion mutant, while the Δsa52 mutant produced an auricin with a demethylated D-forosamine. Although auricin contains a single deoxyhexose, two glycosyltransferase genes were found to participate in the attachment of D-forosamine to the auricin aglycon. An analysis of the expression of the D-forosamine biosynthesis genes revealed that the initial D-forosamine biosynthetic genes aur1TQSV are regulated together with the other auricin core genes by the aur1Ap promoter under the control of the auricin-specific activator Aur1P. The expression of the other D-forosamine genes, however, is governed by promoters differentially dependent upon the two SARP family auricin-specific activators Aur1PR3 and Aur1PR4. These promoters contain direct repeats similar to the SARP consensus sequence and are involved in the interaction with both regulators.
last changed 2017/09/07 12:12

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