Project description:The genus Amycolatopsis is a member of the phylogenetic group nocardioform actinomycetes. Most of the members of the genus Amycolatopsis are known to produce antibiotics. Additionally, members of this genus have been reported to metabolize aromatic compounds as the sole sources of carbon and energy. Development of genetic manipulation in Amycolatopsis has progressed slowly due to paucity of genetic tools and methods. The occurrence of indigenous plasmids in different species of Amycolatopsis is not very common. Till date, only three indigenous plasmids viz., pMEA100, pMEA300 and pA387 have been reported in Amycolatopsis species. Various vectors based on the indigenous plasmids, pMEA100, pMEA300 and pA387, have been constructed. These vectors have proved useful for molecular genetics studies of actinomycetes. Molecular genetic work with Amycolatopsis strains is not easy, since transformation methods have to be developed, or at least optimized, for each particular strain. Nonetheless, methods for efficient transformation (polyethyleneglycol (PEG) induced protoplast transformation, transformation by electroporation and direct transformation) have been developed and used successfully for the introduction of DNA into several Amycolatopsis species. The construction of plasmid cloning vectors and the development of gene transfer systems has opened up possibilities for studying the molecular genetics of these bacteria.
Project description:Strains belonging to the genus Amycolatopsis are well known for the production of a number of important antimicrobials and other bioactive molecules. In this study, we have sequenced the genomes of five Amycolatopsis strains including Amycolatopsis circi DSM 45561T, Amycolatopsis palatopharyngis DSM 44832T and Amycolatopsis thermalba NRRL B-24845T. The genome sequences were analyzed with 52 other publically available Amycolatopsis genomes, representing 34 species, and 12 representatives from related genera including Saccharomonospora, Saccharopolyspora, Saccharothrix, Pseudonocardia and Thermobispora. Based on the core genome phylogeny, Amycolatopsis strains were subdivided into four major clades and several singletons. The genus Amycolatopsis is homogeneous with only three strains noted to group with other genera. Amycolatopsis halophila YIM93223T is quite distinct from other Amycolatopsis strains, both phylogenetically and taxonomically, and belongs to a distinct genus. In addition, Amycolatopsis palatopharyngis DSM 44832T and Amycolatopsis marina CGMCC4 3568T grouped in a clade with Saccharomonospora strains and showed similar taxogenomic differences to this genus as well as other Amycolatopsis strains. The study found a number of strains, particularly those identified as Amycolatopsis orientalis, whose incorrect identification could be resolved by taxogenomic analyses. Similarly, some unclassified strains could be assigned with species designations. The genome sequences of some strains that were independently sequenced by different laboratories were almost identical (99-100% average nucleotide and amino acid identities) consistent with them being the same strain, and confirming the reproducibility and robustness of genomic data. These analyses further demonstrate that whole genome sequencing can reliably resolve intra- and, inter-generic structures and should be incorporated into prokaryotic systematics.
Project description:The genus Amycolatopsis is well known for its ability to produce antibiotics, and an increasing number of valuable biotechnological applications, such as bioremediation, biodegradation, bioconversion, and potentially biofuel, that use this genus have been developed. Amycolatopsis mediterranei is an industrial-scale producer of the important antibiotic rifamycin, which plays a vital role in antimycobacterial therapy. Genetic studies of Amycolatopsis species have progressed slowly due to the lack of efficient transformation methods and stable plasmid vectors. In A. mediterranei U32, electroporation and replicable plasmid vectors have been developed. Here, we establish a simple and efficient conjugal system by transferring integrative plasmid pDZL802 from ET12567 (pUZ8002) to A. mediterranei U32, with an efficiency of 4 × 10-5 CFU per recipient cell. This integrative vector, based on the ?BT1 int-attP locus, is a stable and versatile tool for A. mediterranei U32, and it may also be applicable to various other Amycolatopsis species for strain improvement, heterologous protein expression, and synthetic biology experiments.
Project description:Amycolatopsis rifamycinica DSM 46095 is an actinobacterium that produces rifamycin SV, an antibiotic used against Mycobacterium tuberculosis. Here, we present the draft genome of DSM 46095, which harbors a novel rifamycin polyketide biosynthetic gene cluster (rif PKS) that differed by 10% in nucleotide sequence from the already reported rif PKS cluster of Amycolatopsis mediterranei S699.
Project description:Amycolatopsis orientalis is the producer of vancomycin, a glycopeptide antibiotic that is used for the treatment of serious infections with Gram-positive bacteria. Here we present the next-generation sequencing (NGS)-based 9.06-Mb draft genome sequence of the type strain Amycolatopsis orientalis subsp. orientalis KCTC 9412 (DSM 40040; ATCC 19795).
Project description:BACKGROUND: Amycolatopsis orientalis is the type species of the genus and its industrial strain HCCB10007, derived from ATCC 43491, has been used for large-scale production of the vital antibiotic vancomycin. However, to date, neither the complete genomic sequence of this species nor a systemic characterization of the vancomycin biosynthesis cluster (vcm) has been reported. With only the whole genome sequence of Amycolatopsis mediterranei available, additional complete genomes of other species may facilitate intra-generic comparative analysis of the genus. RESULTS: The complete genome of A. orientalis HCCB10007 comprises an 8,948,591-bp circular chromosome and a 33,499-bp dissociated plasmid. In total, 8,121 protein-coding sequences were predicted, and the species-specific genomic features of A. orientalis were analyzed in comparison with that of A. mediterranei. The common characteristics of Amycolatopsis genomes were revealed via intra- and inter-generic comparative genomic analyses within the domain of actinomycetes, and led directly to the development of sequence-based Amycolatopsis molecular chemotaxonomic characteristics (MCCs). The chromosomal core/quasi-core and non-core configurations of the A. orientalis and the A. mediterranei genome were analyzed reciprocally, with respect to further understanding both the discriminable criteria and the evolutionary implementation. In addition, 26 gene clusters related to secondary metabolism, including the 64-kb vcm cluster, were identified in the genome. Employing a customized PCR-targeting-based mutagenesis system along with the biochemical identification of vancomycin variants produced by the mutants, we were able to experimentally characterize a halogenase, a methyltransferase and two glycosyltransferases encoded in the vcm cluster. The broad substrate spectra characteristics of these modification enzymes were inferred. CONCLUSIONS: This study not only extended the genetic knowledge of the genus Amycolatopsis and the biochemical knowledge of vcm-related post-assembly tailoring enzymes, but also developed methodology useful for in vivo studies in A. orientalis, which has been widely considered as a barrier in this field.
Project description:Genome mining tools have enabled us to predict biosynthetic gene clusters that might encode compounds with valuable functions for industrial and medical applications. With the continuously increasing number of genomes sequenced, we are confronted with an overwhelming number of predicted clusters. In order to guide the effective prioritization of biosynthetic gene clusters towards finding the most promising compounds, knowledge about diversity, phylogenetic relationships and distribution patterns of biosynthetic gene clusters is necessary.Here, we provide a comprehensive analysis of the model actinobacterial genus Amycolatopsis and its potential for the production of secondary metabolites. A phylogenetic characterization, together with a pan-genome analysis showed that within this highly diverse genus, four major lineages could be distinguished which differed in their potential to produce secondary metabolites. Furthermore, we were able to distinguish gene cluster families whose distribution correlated with phylogeny, indicating that vertical gene transfer plays a major role in the evolution of secondary metabolite gene clusters. Still, the vast majority of the diverse biosynthetic gene clusters were derived from clusters unique to the genus, and also unique in comparison to a database of known compounds. Our study on the locations of biosynthetic gene clusters in the genomes of Amycolatopsis' strains showed that clusters acquired by horizontal gene transfer tend to be incorporated into non-conserved regions of the genome thereby allowing us to distinguish core and hypervariable regions in Amycolatopsis genomes.Using a comparative genomics approach, it was possible to determine the potential of the genus Amycolatopsis to produce a huge diversity of secondary metabolites. Furthermore, the analysis demonstrates that horizontal and vertical gene transfer play an important role in the acquisition and maintenance of valuable secondary metabolites. Our results cast light on the interconnections between secondary metabolite gene clusters and provide a way to prioritize biosynthetic pathways in the search and discovery of novel compounds.
Project description:Amycolatopsis mediterranei U32 is an industrial producer of rifamycin SV, whose derivatives have long been the first-line antimycobacterial drugs. In order to perform genetic modification in this important industrial strain, a lot of efforts have been made in the past decades and a homologous recombination-based method was successfully developed in our laboratory, which, however, requires the employment of an antibiotic resistance gene for positive selection and did not support convenient markerless gene deletion. Here in this study, the clustered regularly interspaced short palindromic repeat (CRISPR) system was employed to establish a genome editing system in A. mediterranei U32. Specifically, the Francisella tularensis subsp. novicida Cas12a (FnCas12a) gene was first integrated into the U32 genome to generate target-specific double-stranded DNA (dsDNA) breaks (DSBs) under the guidance of CRISPR RNAs (crRNAs). Then, the DSBs could be repaired by either the non-homologous DNA end-joining (NHEJ) system or the homology-directed repair (HDR) pathway, generating inaccurate or accurate mutations in target genes, respectively. Besides of A. mediterranei, the present work may also shed light on the development of CRISPR-assisted genome editing systems in other species of the Amycolatopsis genus.
Project description:We report the 8.5-Mb genome sequence of Amycolatopsis decaplanina strain DSM 44594(T), isolated from a soil sample from India. The draft genome of strain DSM 44594(T) consists of 8,533,276 bp with a 68.6% G+C content, 7,899 protein-coding genes, and 57 RNAs.
Project description:Actinobacteria are gram-positive filamentous bacteria which contains some of the most deadly human pathogens (Mycobacterium tuberculosis, M. leprae, Corynebacterium diphtheriae, Nocardia farcinica), plant pathogens (Streptomyces scabies, Leifsonia xyli) along with organisms that produces antibiotic (Streptomycetes, Amycolatopsis, Salinospora). Interestingly, these bacteria are equipped with an extraordinary capability of producing antibiotics and other metabolites which have medicinal properties. With the advent of inexpensive genome sequencing techniques and their clinical importance, many genomes of Actinobacteria have been successfully sequenced. These days, with the constant increasing number of drug-resistant bacteria, the urgent need for discovering new antibiotics has emerged as a major scientific challenge. And, unfortunately the traditional method of screening bacterial strains for the production of antibiotics has decreased leading to a paradigm shift in the planning and execution of discovery of novel biosynthetic gene clusters via genome mining process. The entire focus has shifted to the evaluation of genetic capacity of organisms for metabolite production and activation of cryptic gene clusters. This has been made possible only due to the availability of genome sequencing and has been augmented by genomic studies and new biotechnological approaches. Through this article, we present the analysis of the genomes of species belonging to the genus Amycolatopsis, sequenced till date with a focus on completely sequenced genomes and their application for further studies.