Defining mycobacteria: Shared and specific genome features for different lifestyles
- 1 March 2009
- journal article
- research article
- Published by Springer Nature in Indian Journal of Microbiology
- Vol. 49 (1), 11-47
- https://doi.org/10.1007/s12088-009-0006-0
Abstract
During the last decade, the combination of rapid whole genome sequencing capabilities, application of genetic and computational tools, and establishment of model systems for the study of a range of species for a spectrum of biological questions has enhanced our cumulative knowledge of mycobacteria in terms of their growth properties and requirements. The adaption of the corynebacterial surrogate system has simplified the study of cell wall biosynthetic machinery common to actinobacteria. Comparative genomics supported by experimentation reveals that superimposed on a common core of ‘mycobacterial’ gene set, pathogenic mycobacteria are endowed with multiple copies of several protein families that encode novel secretion and transport systems such as mce and esx; immunomodulators named PE/PPE proteins, and polyketide synthases for synthesis of complex lipids. The precise timing of expression, engagement and interactions involving one or more of these redundant proteins in their host environments likely play a role in the definition and differentiation of species and their disease phenotypes. Besides these, only a few species specific ‘virulence’ factors i.e., macromolecules have been discovered. Other subtleties may also arise from modifications of shared macromolecules. In contrast, to cope with the broad and changing growth conditions, their saprophytic relatives have larger genomes, in which the excess coding capacity is dedicated to transcriptional regulators, transporters for nutrients and toxic metabolites, biosynthesis of secondary metabolites and catabolic pathways. In this review, we present a sampling of the tools and techniques that are being implemented to tease apart aspects of physiology, phylogeny, ecology and pathology and illustrate the dominant genomic characteristics of representative species. The investigation of clinical isolates, natural disease states and discovery of new diagnostics, vaccines and drugs for existing and emerging mycobacterial diseases, particularly for multidrug resistant strains are the challenges in the coming decades.Keywords
This publication has 131 references indexed in Scilit:
- PapA1 and PapA2 are acyltransferases essential for the biosynthesis of theMycobacterium tuberculosisvirulence factor Sulfolipid-1Proceedings of the National Academy of Sciences, 2007
- Identification ofMycobacterium aviumpathogenicity island important for macrophage and amoeba infectionProceedings of the National Academy of Sciences, 2007
- Genome plasticity of BCG and impact on vaccine efficacyProceedings of the National Academy of Sciences, 2007
- A gene cluster encoding cholesterol catabolism in a soil actinomycete provides insight into Mycobacterium tuberculosis survival in macrophagesProceedings of the National Academy of Sciences, 2007
- Biosynthesis of mycobacterial lipoarabinomannan: Role of a branching mannosyltransferaseProceedings of the National Academy of Sciences, 2006
- Massive gene decay in the leprosy bacillusNature, 2001
- Database resources of the National Center for Biotechnology InformationNucleic Acids Research, 2000
- Deciphering the biology of Mycobacterium tuberculosis from the complete genome sequenceNature, 1998
- A Chemotaxonomic Study of the Lipoglycans of Rhodococcus rhodnii N445 (NCIMB 11279)Zentralblatt für Bakteriologie, 1996
- The phenolic mycoside of Mycobacterium ulcerans: structure and taxonomic implicationsJournal of General Microbiology, 1992