1. |
Guo Y,
Zheng W,
Rong X,
Huang Y,
( 2008 ) A multilocus phylogeny of the Streptomyces griseus 16S rRNA gene clade: use of multilocus sequence analysis for streptomycete systematics. PMID : 18175701 : DOI : 10.1099/ijs.0.65224-0 Abstract >>
Streptomycetes are a complex group of actinomycetes that produce diverse bioactive metabolites of commercial significance. Systematics can provide a useful framework for identifying species that may produce novel metabolites. However, previously proposed approaches to the systematics of Streptomyces have suffered from either poor interlaboratory comparability or insufficient resolution. In particular, the Streptomyces griseus 16S rRNA gene clade is the most challenging and least defined group within the genus Streptomyces in terms of phylogeny. Here we report the results of a multilocus sequence analysis scheme developed to address the phylogeny of this clade. Sequence fragments of six housekeeping genes, atpD, gyrB, recA, rpoB, trpB and 16S rRNA, were obtained for 53 reference strains that represent 45 valid species and subspecies. Analysis of each individual locus confirmed the suitability of loci and the congruence of single-gene trees for concatenation. Concatenated trees of three, four, five and all six genes were constructed, and the stability of the topology and discriminatory power of each tree were analysed. It can be concluded from the results that phylogenetic analysis based on multilocus sequences is more accurate and robust for species delineation within Streptomyces. A multilocus phylogeny of six genes proved to be optimal for elucidating the interspecies relationships within the S. griseus 16S rRNA gene clade. Our multilocus sequence analysis scheme provides a valuable tool that can be applied to other Streptomyces clades for refining the systematic framework of this genus.
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2. |
Waldman AJ,
Pechersky Y,
Wang P,
Wang JX,
Balskus EP,
( 2015 ) The Cremeomycin Biosynthetic Gene Cluster Encodes a Pathway for Diazo Formation. PMID : 26278892 : DOI : 10.1002/cbic.201500407 PMC : PMC4996270 Abstract >>
Diazo groups are found in a range of natural products that possess potent biological activities. Despite longstanding interest in these metabolites, diazo group biosynthesis is not well understood, in part because of difficulties in identifying specific genes linked to diazo formation. Here we describe the discovery of the gene cluster that produces the o-diazoquinone natural product cremeomycin and its heterologous expression in Streptomyces lividans. We used stable isotope feeding experiments and in vitro characterization of biosynthetic enzymes to decipher the order of events in this pathway and establish that diazo construction involves late-stage N-N bond formation. This work represents the first successful production of a diazo-containing metabolite in a heterologous host, experimentally linking a set of genes with diazo formation.
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3. |
Katsuyama Y,
Sato Y,
Sugai Y,
Higashiyama Y,
Senda M,
Senda T,
Ohnishi Y,
( 2018 ) Crystal structure of the nitrosuccinate lyase CreD in complex with fumarate provides insights into the catalytic mechanism for nitrous acid elimination. PMID : 29505698 : DOI : 10.1111/febs.14429 Abstract >>
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