| Structural highlights
Function
ARFA_MYCTU Probably plays a role in ammonia secretion that neutralizes the medium at pH 5.5, although it does not play a direct role in ammonia transport. The OmpA-like domain (196-326) binds M.tuberculosis peptidoglycan. Overexpression in M.bovis or M.smegmatis gives channels with average conductance value of 1,600 +/- 100 pS, but this may not be physiologically relevant.[1] [2] [3]
Publication Abstract from PubMed
Rv0899 from Mycobacterium tuberculosis belongs to the OmpA (outer membrane protein A) family of outer membrane proteins. It functions as a pore-forming protein; the deletion of this gene impairs the uptake of some water-soluble substances, such as serine, glucose, and glycerol. Rv0899 has also been shown to play a part in low-pH environment adaption, which may play a part in pathogenic mycobacteria overcoming the host's defense mechanisms. Based on many bacterial physiological data and recent structural studies, it was proposed that Rv0899 forms an oligomeric channel to carry out such functions. In this work, biochemical and structural data obtained from solution NMR and EPR spectroscopy indicated that Rv0899 is a monomeric membrane-anchoring protein with two separate domains, rather than an oligomeric pore. Using NMR chemical shift perturbation and isothermal calorimetric titration assays, we show that Rv0899 was able to interact with Zn(2+) ions, which may indicate a role for Rv0899 in the process of Zn(2+) acquisition.
Structural Studies of Mycobacterium tuberculosis Rv0899 Reveal a Monomeric Membrane-Anchoring Protein with Two Separate Domains.,Li J, Shi C, Gao Y, Wu K, Shi P, Lai C, Chen L, Wu F, Tian C J Mol Biol. 2011 Nov 15. PMID:22108166[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Raynaud C, Papavinasasundaram KG, Speight RA, Springer B, Sander P, Bottger EC, Colston MJ, Draper P. The functions of OmpATb, a pore-forming protein of Mycobacterium tuberculosis. Mol Microbiol. 2002 Oct;46(1):191-201. PMID:12366842
- ↑ Alahari A, Saint N, Campagna S, Molle V, Molle G, Kremer L. The N-terminal domain of OmpATb is required for membrane translocation and pore-forming activity in mycobacteria. J Bacteriol. 2007 Sep;189(17):6351-8. doi: 10.1128/JB.00509-07. Epub 2007 Jun 15. PMID:17573469 doi:http://dx.doi.org/10.1128/JB.00509-07
- ↑ Song H, Huff J, Janik K, Walter K, Keller C, Ehlers S, Bossmann SH, Niederweis M. Expression of the ompATb operon accelerates ammonia secretion and adaptation of Mycobacterium tuberculosis to acidic environments. Mol Microbiol. 2011 May;80(4):900-18. doi: 10.1111/j.1365-2958.2011.07619.x. Epub, 2011 Mar 16. PMID:21410778 doi:http://dx.doi.org/10.1111/j.1365-2958.2011.07619.x
- ↑ Li J, Shi C, Gao Y, Wu K, Shi P, Lai C, Chen L, Wu F, Tian C. Structural Studies of Mycobacterium tuberculosis Rv0899 Reveal a Monomeric Membrane-Anchoring Protein with Two Separate Domains. J Mol Biol. 2011 Nov 15. PMID:22108166 doi:10.1016/j.jmb.2011.11.016
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