scholarly journals Identification of the Biosynthetic Gene Cluster and an Additional Gene for Resistance to the Antituberculosis Drug Capreomycin

2007 ◽  
Vol 73 (13) ◽  
pp. 4162-4170 ◽  
Author(s):  
Elizabeth A. Felnagle ◽  
Michelle R. Rondon ◽  
Andrew D. Berti ◽  
Heidi A. Crosby ◽  
Michael G. Thomas
Keyword(s):  
Gene Cluster ◽  
Resistance Gene ◽  
Aminoglycoside Antibiotic ◽  
Biosynthetic Gene Cluster ◽  
Multidrug Resistant ◽  
23S Rrna ◽  
Peptide Antibiotics ◽  
Biosynthetic Gene ◽  
Essential Components ◽  
Initial Work

ABSTRACT Capreomycin (CMN) belongs to the tuberactinomycin family of nonribosomal peptide antibiotics that are essential components of the drug arsenal for the treatment of multidrug-resistant tuberculosis. Members of this antibiotic family target the ribosomes of sensitive bacteria and disrupt the function of both subunits of the ribosome. Resistance to these antibiotics in Mycobacterium species arises due to mutations in the genes coding for the 16S or 23S rRNA but can also arise due to mutations in a gene coding for an rRNA-modifying enzyme, TlyA. While Mycobacterium species develop resistance due to alterations in the drug target, it has been proposed that the CMN-producing bacterium, Saccharothrix mutabilis subsp. capreolus, uses CMN modification as a mechanism for resistance rather than ribosome modification. To better understand CMN biosynthesis and resistance in S. mutabilis subsp. capreolus, we focused on the identification of the CMN biosynthetic gene cluster in this bacterium. Here, we describe the cloning and sequence analysis of the CMN biosynthetic gene cluster from S. mutabilis subsp. capreolus ATCC 23892. We provide evidence for the heterologous production of CMN in the genetically tractable bacterium Streptomyces lividans 1326. Finally, we present data supporting the existence of an additional CMN resistance gene. Initial work suggests that this resistance gene codes for an rRNA-modifying enzyme that results in the formation of CMN-resistant ribosomes that are also resistant to the aminoglycoside antibiotic kanamycin. Thus, S. mutabilis subsp. capreolus may also use ribosome modification as a mechanism for CMN resistance.

scholarly journals Deciphering Tuberactinomycin Biosynthesis: Isolation, Sequencing, and Annotation of the Viomycin Biosynthetic Gene Cluster

2003 ◽  
Vol 47 (9) ◽  
pp. 2823-2830 ◽  
Author(s):  
Michael G. Thomas ◽  
Yolande A. Chan ◽  
Sarah G. Ozanick
Keyword(s):  
Gene Cluster ◽  
Bacterial Infections ◽  
Biosynthetic Gene Cluster ◽  
Multidrug Resistant ◽  
Open Reading Frames ◽  
Combinatorial Biosynthesis ◽  
Biosynthetic Gene ◽  
Resistant Tuberculosis ◽  
Multidrug Resistant Tuberculosis ◽  
Essential Components

ABSTRACT The tuberactinomycin antibiotics are essential components in the drug arsenal against Mycobacterium tuberculosis infections and are specifically used for the treatment of multidrug-resistant tuberculosis. These antibiotics are also being investigated for their targeting of the catalytic RNAs involved in viral replication and for the treatment of bacterial infections caused by methicillin-resistant Staphylococcus aureus strains and vancomycin-resistant enterococci. We report on the isolation, sequencing, and annotation of the biosynthetic gene cluster for one member of this antibiotic family, viomycin, from Streptomyces sp. strain ATCC 11861. This is the first gene cluster for a member of the tuberactinomycin family of antibiotics sequenced, and the information gained can be extrapolated to all members of this family. The gene cluster covers 36.3 kb of DNA and encodes 20 open reading frames that we propose are involved in the biosynthesis, regulation, export, and activation of viomycin, in addition to self-resistance to the antibiotic. These results enable us to predict the metabolic logic of tuberactinomycin production and begin steps toward the combinatorial biosynthesis of these antibiotics to complement existing chemical modification techniques to produce novel tuberactinomycin derivatives.

scholarly journals Biosynthetic Pathway for Mannopeptimycins, Lipoglycopeptide Antibiotics Active against Drug-Resistant Gram-Positive Pathogens

2006 ◽  
Vol 50 (6) ◽  
pp. 2167-2177 ◽  
Author(s):  
Nathan A. Magarvey ◽  
Brad Haltli ◽  
Min He ◽  
Michael Greenstein ◽  
John A. Hucul
Keyword(s):  
Amino Acid ◽  
Gene Cluster ◽  
Biosynthetic Pathway ◽  
Domain Analysis ◽  
Biosynthetic Gene Cluster ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
Biosynthetic Gene ◽  
Peptide Synthetases ◽  
Multidrug Resistant Pathogens

ABSTRACT The mannopeptimycins are a novel class of lipoglycopeptide antibiotics active against multidrug-resistant pathogens with potential as clinically useful antibacterials. This report is the first to describe the biosynthesis of this novel class of mannosylated lipoglycopeptides. Included here are the cloning, sequencing, annotation, and manipulation of the mannopeptimycin biosynthetic gene cluster from Streptomyces hygroscopicus NRRL 30439. Encoded by genes within the mannopeptimycin biosynthetic gene cluster are enzymes responsible for the generation of the hexapeptide core (nonribosomal peptide synthetases [NRPS]) and tailoring reactions (mannosylation, isovalerylation, hydroxylation, and methylation). The NRPS system is noncanonical in that it has six modules utilizing only five amino acid-specific adenylation domains and it lacks a prototypical NRPS macrocyclizing thioesterase domain. Analysis of the mannopeptimycin gene cluster and its engineering has elucidated the mannopeptimycin biosynthetic pathway and provides the framework to make new and improved mannopeptimycins biosynthetically.

scholarly journals Identification of polyketide biosynthetic gene clusters that harbor self-resistance target genes

2020 ◽  
Author(s):  
Gergana A Vandova ◽  
Aleksandra Nivina ◽  
Chaitan Khosla ◽  
Ronald W Davis ◽  
Curt R Fisher ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Gene Clusters ◽  
Biosynthetic Gene Cluster ◽  
The Self ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Automated Method ◽  
Novel Antibiotics

AbstractBackgroundPolyketide secondary metabolites have been a rich source of antibiotic discovery for decades. Thousands of novel polyketide synthase (PKS) gene clusters have been identified in recent years with advances in DNA sequencing. However, experimental characterization of novel and useful PKS activities remains complicated. As a result, computational tools to analyze sequence data are essential to identify and prioritize potentially novel PKS activities. Here we exploit the concept of genetically-encoded self-resistance to identify and rank biosynthetic gene clusters for their potential to encode novel antibiotics.ResultsTo identify PKS genes that are likely to produce an antibacterial compound, we developed an automated method to identify and catalog clusters that harbor potential self-resistance genes. We manually curated a list of known self-resistance genes and searched all NCBI genome databases for homologs of these self-resistance genes in biosynthetic gene clusters. The algorithm takes into account (1) the distance of the potential self-resistance gene to a core enzyme in the biosynthetic gene cluster; (2) the presence of a duplicated housekeeping copy of the self-resistance gene; (3) the presence of close homologs of the biosynthetic gene cluster in diverse species also harboring the putative self-resistance gene; (4) evidence for coevolution of the self-resistance gene and core biosynthetic gene; and (5) self-resistance gene ubiquity. We generated a catalog of 190 unique PKS clusters whose products likely target known enzymes of antibacterial importance. We also present an expanded set of putative self-resistance genes that may be useful in identifying small molecules active against novel microbial targets.ConclusionsWe developed a bioinformatic approach to identify and rank biosynthetic gene clusters that likely harbor self-resistance genes and may produce compounds with antibacterial properties. We compiled a list of putative self-resistance genes for novel antibacterial targets, and of orphan PKS clusters harboring these targets. These catalogues are a resource for discovery of novel antibiotics.

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

2017 ◽  
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 <i>Anabaena</i>. 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 (<b>1</b>), from <i>Sphaerospermopsis</i> sp. LEGE 00249. The anacyclamide biosynthetic gene cluster (<i>acy</i>) encoding the novel macrocyclic prenylated cyanobactin, was sequenced. Heterologous expression of the acy gene cluster in <i>Escherichia</i> <i>coli</i> established the connection between genomic and mass spectrometric data. Unambiguous establishment of the type and site of prenylation required the full structural elucidation of <b>1</b> using Nuclear Magnetic Resonance (NMR), which demonstrated that a forward prenylation occurred on the tyrosine residue. Compound <b>1</b> was tested in pharmacologically or ecologically relevant biological assays and revealed moderate antimicrobial activity towards the fouling bacterium <i>Halomonas aquamarina</i> CECT 5000.<br>

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