Mycobacterium tuberculosis Rv0899 defines a family of membrane proteins widespread in nitrogen-fixing bacteria. Proteins 2011 Oct;79(10):2946-55
Date
09/10/2011Pubmed ID
21905117Pubmed Central ID
PMC3172613DOI
10.1002/prot.23151Scopus ID
2-s2.0-80052576378 (requires institutional sign-in at Scopus site) 3 CitationsAbstract
The Mycobacterium tuberculosis membrane protein Rv0899 confers adaptation of the bacterium to acidic environments. Due to strong sequence homology of its C-terminus to bacterial OmpA-like domains, Rv0899 has been proposed to constitute an outer membrane porin of M. tuberculosis. However, OmpA-like domains are widespread in a wide variety of bacterial proteins with different functions. Furthermore, the three-dimensional structure of Rv0899 does not contain a transmembrane β-barrel, and recent evidence demonstrates that it does not have porin activity. Instead, the rv0899 gene is part of an operon (rv0899-rv0901) that is required for fast ammonia secretion, pH neutralization, and growth of M. tuberculosis in acidic environments. The mechanism whereby these functions are accomplished is not known. To gain further functional insights, a targeted search of the genomic databases was performed for proteins with sequence similarity beyond the OmpA-like C-terminus. The results presented here, show that Rv0899-like proteins are widespread in bacteria with functions in nitrogen metabolism, adaptation to nutrient poor environments, and/or establishing symbiosis with the host organism, and appear to form a protein family. These findings suggest that M. tuberculosis Rv0899 may also assist similar processes and lend further support to its role in ammonia secretion and M. tuberculosis adaptation to the host environment.
Author List
Marassi FMAuthor
Francesca M. Marassi PhD Chair, Professor in the Biophysics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Amino Acid SequenceBacterial Proteins
Databases, Protein
Membrane Proteins
Molecular Sequence Data
Mycobacterium tuberculosis
Nitrogen Fixation
Phylogeny
Porins
Sequence Homology, Amino Acid
