EC Number   |
General Information |
Reference |
|---|
   2.4.1.345 | metabolism |
PimA undergoes a conformational reorganization of its N-terminal domain upon phosphatidylinositol membrane interaction.The presence of anionic phospholipids increases the susceptibility of PimA to proteolysis |
-, 741039 |
| 2.4.1.345 | physiological function |
both mannosyltransferases PimA and PimB' (MSMEG_4253) recognize phosphatidyl-myo-inositol as a lipid acceptor. PimA specifically catalyzes the transfer of a mannopyranosyl residue to the 2-position of the myo-inositol ring of phosphatidylinositol, whereas PimB' exclusively transfers to the 6-position. PimB' can catalyze the transfer of a mannopyranosyl residue onto the phosphatidylinositol-monomannoside (PIM1) product of PimA, while PimA is unable in vitro to transfer mannopyranosyl onto the PIM1 product of PimB' |
-, 704533 |
| 2.4.1.345 | physiological function |
downregulation of PimA expression causes bactericidality in batch cultures associated with markedly reduced levels of phosphatidyl-myo-inositol dimannosides. PimA is required for viability during macrophage infection. In two different mouse models of infection a dramatic decrease in viable counts is observed upon silencing of the gene. Depletion of PimA results in complete clearance of the mouse lungs during both the acute and chronic phases of infection |
-, 736363 |
| 2.4.1.345 | physiological function |
PimA is involved in the metabolic pathway producing phosphatidylinositol dimannoside PIM2 and phosphatidylinositol hexamannosidePIM6. Crude extracts from Escherichia coli producing recombinant PimA protein synthesize diacylated phosphatidylinositol mono-mannoside from GDP-[14C]Man and bovine phosphatidylinositol. A conditional mutant is unable to grow at the higher temperature at which the rescue plasmid is lost. The synthesis of phosphatidylinositol mono-mannosides and derived higher phosphatidylinositol mannosides appears to be dependent on PimA and essential for growth |
-, 659183 |
| 2.4.1.345 | physiological function |
PimA preferentially binds to negatively charged phosphatidyl-myo-inositol substrate and non-substrate membrane model systems (small unilamellar vesicle) through its N-terminal domain, inducing an important structural reorganization of anionic phospholipids. This interaction is mainly mediated by amphipathic helix alpha2, which undergoes a substantial conformational change and localizes in the vicinity of the negatively charged lipid headgroups and the very first carbon atoms of the acyl chains, at the PimA-phospholipid interface. A flexible region within the N-terminal domain undergoes beta-strand-to-alpha-helix and alpha-helix-to-beta-strand transitions during catalysis and interacts with anionic phospholipids, but the effect is markedly less pronounced to that observed for the amphipathic helix alpha2 |
-, 740749 |
| 2.4.1.345 | physiological function |
the stoichiometry of the enzyme-substrate complex strongly depends on phosphatidylinositol concentration. The protein is able to interact with mono-disperse phosphatidylinositol through its active site cleft and also with phospholipid aggregates (micelles or liposomes), possibly through a different region of the protein. The latter interactions stimulate the catalytic activity |
-, 680790 |
