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B6db references: 19778043

type Journal Article
authors Heemstra JR Jr, Walsh CT, Sattely ES
title Enzymatic tailoring of ornithine in the biosynthesis of the Rhizobium cyclic trihydroxamate siderophore vicibactin
journal J Am Chem Soc
Activity vbsl
Family vbsl
PLP Fold Type 1
sel selected
ui 19778043
year (2009)
volume 13
number 42
pages 15317-29
keywords doi: 10.1021/ja9056008
abstract To acquire iron, the N(2)-fixing, symbiotic bacterium Rhizobium sp. produce the cyclic trihydroxamate siderophore vicibactin, containing a 30-membered trilactone scaffold. Herein we report the overproduction and purification of the six proteins VbsACGOLS in the bacterial host Escherichia coli and the reconstitution of the biosynthesis of vicibactin from primary metabolites. The flavoprotein VbsO acts as a pathway-initiating l-ornithine N(5)-hydroxylase, followed by VbsA, which transfers (R)-3-hydroxybutyryl- from the CoA thioester to N(5)-hydroxyornithine to yield N(5)-((R)-3-hydroxybutyryl)-N(5)-hydroxy-l-ornithine. VbsL is a PLP-dependent epimerase acting at C(2) of the 10 atom monomer unit. VbsS, a nonribosomal peptide synthetase free-standing module, then activates N(5)-((R)-3-hydroxybutyryl)-N(5)-hydroxy-d-ornithine as the AMP anhydride on the way to cyclotrimerization to the vicibactin scaffold. The last step, tris-acetylation of the C(2) amino group of desacetyl-d-vicibactin to the mature siderophore vicibactin, is catalyzed distributively by VbsC, using three molecules of acetyl-CoA.
last changed 2019/05/17 08:52

B6db references