Processing 2-Methyl-<scp>l</scp>-Tryptophan through Tandem Transamination and Selective Oxygenation Initiates Indole Ring Expansion in the Biosynthesis of Thiostrepton
作者:Zhi Lin、Jia Ji、Shuaixiang Zhou、Fang Zhang、Jiequn Wu、Yinlong Guo、Wen Liu
DOI:10.1021/jacs.7b05337
日期:2017.9.6
We here report that during the formation of QA, the key expansion of an indole to a quinoline relies on the activities of the pyridoxal-5'-phosphate-dependent protein TsrA and the flavoprotein TsrE. These proteins act in tandem to process the precursor 2-methyl- l-Trp through reversible transamination and selective oxygenation, thereby initiating a highly reactive rearrangement in which selective C2-N1
Chemoenzymatic Synthesis of Indole-Containing Acyloin Derivatives
作者:Saad Alrashdi、Federica Casolari、Aziz Alabed、Kwaku Kyeremeh、Hai Deng
DOI:10.3390/molecules28010354
日期:——
neocarazostatin A. The utilization of the first two enzymes, the PfTrpB variant and LAAO, is designed to provide structurally diverse indole 3-pyruvate derivatives as donor substrates for NzsH-catalysed biotransformation to provide acyloin derivatives. Our results demonstrate that NzsH displays a considerable substrate profile toward donor substrates for production of acyloins with different indole ring
Thiostrepton Biosynthesis: Prototype for a New Family of Bacteriocins
作者:Wendy L. Kelly、Lisa Pan、Chaoxuan Li
DOI:10.1021/ja807890a
日期:2009.4.1
Thiopeptide antibiotics are a group of highly modified peptide metabolites. The defining scaffold for the thiopeptides is a macrocycle containing a dehydropiperidine or pyridine ring, dehydrated amino acids, and multiple thiazole or oxazole rings. Some members of the thiopeptides, such as thiostrepton, also contain either a quinaldic acid or indolic acid substituent derived from tryptophan. Although the amino acid precursors of these metabolites are well-established, the biogenesis of these complex peptides has remained elusive. Whole-genome scanning of Streptomyces laurentii permitted identification of a thiostrepton prepeptide, TsrA, and involvement of TsrA in thiostrepton biosynthesis was confirmed by mutagenesis. A gene cluster responsible for thiostrepton biosynthesis is reported, and the encoded gene products are discussed. The disruption of a gene encoding an amidotransferase, tsrT, led to the loss of thiostrepton production and the detection of a new metabolite, contributing further support to the identification of the tsr cluster. The tsr locus also appears to possess the gene products needed to convert tryptophan to the quinaldic acid moiety, and an aminotransferase was found to catalyze an early step in this pathway. This work establishes that the thiopeptides are a type of bacteriocin, a family of genetically encoded antimicrobial peptides, and are subjected to extensive posttranslational modification during maturation of the prepeptide.