Identification of the gene encoding an N-acetylpuromycin N-acetylhydrolase in the puromycin biosynthetic gene cluster from Streptomyces alboniger.

FtsH belongs to the AAA+ ATP-dependent family of proteases, which participate in diverse cellular processes and are ubiquitous among bacteria, chloroplasts, and mitochondria. FtsH is poorly characterized in most organisms, especially compared to other major housekeeping proteases. In the current study, we examined the source of FtsH essentiality in the human oral microbiome species Streptococcus mutans, one of the primary etiological agents of dental caries. By creating a conditionally lethal ftsH mutant, we were able to identify a secondary suppressor missense mutation in the vicR gene, encoding the response regulator of the essential VicRK two-component system (TCS). Transcriptomic analysis of the vicR (G195R) mutant revealed significantly reduced expression of 46 genes, many of which were located within the genomic island Tnsmu2, which harbors the mutanobactin biosynthetic gene cluster. In agreement with the transcriptomic data, deletion of the mutanobactin biosynthetic gene cluster suppressed ftsH essentiality in S. mutans. We also explored the role of FtsH in S. mutans physiology and demonstrated its critical role in stress tolerance, especially acid stress. The presented results reveal the first insights within S. mutans for the pleiotropic regulatory function of this poorly understood global regulator.

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A comparison of the clavam biosynthetic gene clusters in Streptomyces antibioticus Tü1718 and Streptomyces clavuligerus

Canadian Journal of Microbiology ◽

10.1139/w2012-012 ◽

2012 ◽

Vol 58 (4) ◽

pp. 413-425 ◽

Cited By ~ 5

Author(s):

Sarah Goomeshi Nobary ◽

Susan E. Jensen

Keyword(s):

Clavulanic Acid ◽

Gene Cluster ◽

Gene Clusters ◽

Streptomyces Clavuligerus ◽

Biosynthetic Gene Cluster ◽

Cosmid Library ◽

Biosynthetic Gene ◽

Gene Encoding ◽

Knock Out ◽

Streptomyces Antibioticus

The production of clavam metabolites has been studied previously in Streptomyces clavuligerus , a species that produces clavulanic acid as well as 4 other clavam compounds, but the late steps of the pathway leading to the specific end products are unclear. The present study compared the clavam biosynthetic gene cluster in Streptomyces antibioticus , chosen because it produces only 2 clavam metabolites and no clavulanic acid, with that of S. clavuligerus. A cosmid library of S. antibioticus genomic DNA was screened with a clavaminate synthase-specific probe based on the corresponding genes from S. clavuligerus, and 1 of the hybridizing cosmids was sequenced in full. A clavam gene cluster was identified that shows similarities to that of S. clavuligerus but also contains a number of novel genes. Knock-out mutation of the clavaminate synthase gene abolished clavam production in S. antibioticus, confirming the identity of the gene cluster. Knock-out mutation of a novel gene encoding an apparent oxidoreductase also abolished clavam production. A potential clavam biosynthetic pathway consistent with the genes in the cluster and the metabolites produced by S. antibioticus, and correspondingly different from that of S. clavuligerus, is proposed.

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Anacyclamide D8P, a prenylated cyanobactin from a Sphaerospermopsis sp. cyanobacterium

10.26434/chemrxiv.5346739.v1 ◽

2017 ◽

Cited By ~ 1

Author(s):

Joana Martins ◽

Niina Leikoski ◽

Matti Wahlsten ◽

Joana Azevedo ◽

Jorge Antunes ◽

...

Keyword(s):

Gene Cluster ◽

Cyclic Peptides ◽

Biosynthetic Gene Cluster ◽

The Novel ◽

Tyrosine Residue ◽

Biosynthetic Gene ◽

Post Translational Modification ◽

Biological Assays ◽

Mass Spectrometric Data ◽

Spectrometric Data

Cyanobactins are a family of linear and cyclic peptides produced through the post-translational modification of short precursor peptides. Anacyclamides are macrocyclic cyanobactins with a highly diverse sequence that are common in the genus Anabaena. A mass spectrometry-based screening of potential cyanobactin producers led to the discovery of a new prenylated member of this family of compounds, anacyclamide D8P (1), from Sphaerospermopsis sp. LEGE 00249. The anacyclamide biosynthetic gene cluster (acy) encoding the novel macrocyclic prenylated cyanobactin, was sequenced. Heterologous expression of the acy gene cluster in Escherichia coli established the connection between genomic and mass spectrometric data. Unambiguous establishment of the type and site of prenylation required the full structural elucidation of 1 using Nuclear Magnetic Resonance (NMR), which demonstrated that a forward prenylation occurred on the tyrosine residue. Compound 1 was tested in pharmacologically or ecologically relevant biological assays and revealed moderate antimicrobial activity towards the fouling bacterium Halomonas aquamarina CECT 5000.

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