1u2p | pdb_00001u2p
Crystal structure of Mycobacterium tuberculosis Low Molecular Protein Tyrosine Phosphatase (MPtpA) at 1.9A resolution
Structural highlights
FunctionPTPA_MYCTU Mediates host-pathogen interaction and interferes with vesicular trafficking in the infected macrophage. Inhibits host phagolysosomal fusion in M.tuberculosis-infected macrophages to promote bacteria survival. Dephosphorylates host VPS33B protein, which induces a block of the host phagosome maturation within macrophage cells. Acts on tyrosine phosphorylated proteins, low-MW aryl phosphates and natural and synthetic acyl phosphates. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe low-molecular-weight protein tyrosine phosphatase (LMWPTPase) belongs to a distinctive class of phosphotyrosine phosphatases widely distributed among prokaryotes and eukaryotes. We report here the crystal structure of LMWPTPase of microbial origin, the first of its kind from Mycobacterium tuberculosis. The structure was determined to be two crystal forms at 1.9- and 2.5-A resolutions. These structural forms are compared with those of the LMWPTPases of eukaryotes. Though the overall structure resembles that of the eukaryotic LMWPTPases, there are significant changes around the active site and the protein tyrosine phosphatase (PTP) loop. The variable loop forming the wall of the crevice leading to the active site is conformationally unchanged from that of mammalian LMWPTPase; however, differences are observed in the residues involved, suggesting that they have a role in influencing different substrate specificities. The single amino acid substitution (Leu12Thr [underlined below]) in the consensus sequence of the PTP loop, CTGNICRS, has a major role in the stabilization of the PTP loop, unlike what occurs in mammalian LMWPTPases. A chloride ion and a glycerol molecule were modeled in the active site where the chloride ion interacts in a manner similar to that of phosphate with the main chain nitrogens of the PTP loop. This structural study, in addition to identifying specific mycobacterial features, may also form the basis for exploring the mechanism of the substrate specificities of bacterial LMWPTPases. Crystal structure of low-molecular-weight protein tyrosine phosphatase from Mycobacterium tuberculosis at 1.9-A resolution.,Madhurantakam C, Rajakumara E, Mazumdar PA, Saha B, Mitra D, Wiker HG, Sankaranarayanan R, Das AK J Bacteriol. 2005 Mar;187(6):2175-81. PMID:15743966[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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