Journal
BMC GENOMICS
Volume 8, Issue -, Pages -Publisher
BIOMED CENTRAL LTD
DOI: 10.1186/1471-2164-8-60
Keywords
-
Funding
- NIAID NIH HHS [R21 AI063350, R21AI063350] Funding Source: Medline
Ask authors/readers for more resources
Background: The genome of Mycobacterium tuberculosis harbors four copies of a cluster of genes termed mce operons. Despite extensive research that has demonstrated the importance of these operons on infection outcome, their physiological function remains obscure. Expanding databases of complete microbial genome sequences facilitate a comparative genomic approach that can provide valuable insight into the role of uncharacterized proteins. Results: The M. tuberculosis mce loci each include two yrbE and six mce genes, which have homology to ABC transporter permeases and substrate-binding proteins, respectively. Operons with an identical structure were identified in all Mycobacterium species examined, as well as in five other Actinomycetales genera. Some of the Actinomycetales mce operons include an mkl gene, which encodes an ATPase resembling those of ABC uptake transporters. The phylogenetic profile of Mkl orthologs exactly matched that of the Mce and YrbE proteins. Through topology and motif analyses of YrbE homologs, we identified a region within the penultimate cytoplasmic loop that may serve as the site of interaction with the putative cognate Mkl ATPase. Homologs of the exported proteins encoded adjacent to the M. tuberculosis mce operons were detected in a conserved chromosomal location downstream of the majority of Actinomycetales operons. Operons containing linked mkl, yrbE and mce genes, resembling the classic organization of an ABC importer, were found to be common in Gram-negative bacteria and appear to be associated with changes in properties of the cell surface. Conclusion: Evidence presented suggests that the mce operons of Actinomycetales species and related operons in Gram-negative bacteria encode a subfamily of ABC uptake transporters with a possible role in remodeling the cell envelope.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available