3k6y | pdb_00003k6y
Crystal structure of Rv3671c protease from M. tuberculosis, active form
Structural highlights
FunctionY3671_MYCTU Required for M.tuberculosis resistance to oxidative stress in addition to its role in resistance to acid, which is essential for virulence. It protects M.tuberculosis against phagolysosomal concentrations of acid and maintains its intrabacterial pH when phagocytosed by IFN-gamma-activated macrophages.[1] [2] Publication Abstract from PubMedRv3671c, a putative serine protease, is crucial for persistence of Mycobacterium tuberculosis in the hostile environment of the phagosome. We show that Rv3671c is required for M. tuberculosis resistance to oxidative stress in addition to its role in protection from acidification. Structural and biochemical analyses demonstrate that the periplasmic domain of Rv3671c is a functional serine protease of the chymotrypsin family and, remarkably, that its activity increases on oxidation. High-resolution crystal structures of this protease in an active strained state and in an inactive relaxed state reveal that a solvent-exposed disulfide bond controls the protease activity by constraining two distant regions of Rv3671c and stabilizing it in the catalytically active conformation. In vitro biochemical studies confirm that activation of the protease in an oxidative environment is dependent on this reversible disulfide bond. These results suggest that the disulfide bond modulates activity of Rv3671c depending on the oxidative environment in vivo. Structural insight into serine protease Rv3671c that Protects M. tuberculosis from oxidative and acidic stress.,Biswas T, Small J, Vandal O, Odaira T, Deng H, Ehrt S, Tsodikov OV Structure. 2010 Oct 13;18(10):1353-63. PMID:20947023[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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