4as3 | pdb_00004as3
Pseudomonas Aeruginosa Phosphorylcholine Phosphatase. Orthorhombic form
Structural highlights
FunctionPCHP_PSEAE Catalyzes the hydrolysis of phosphorylcholine (PCho) to produce choline and inorganic phosphate (PubMed:10387109, PubMed:15886911, PubMed:17106798, PubMed:2116592). Can also hydrolyze phosphorylethanolamine and the nonphysiological substrate p-nitrophenylphosphate (pNPP) (PubMed:10387109, PubMed:15886911, PubMed:17106798, PubMed:2116592). Shows higher affinity and catalytic efficiency with phosphorylcholine as substrate (PubMed:2116592).[1] [2] [3] [4] Is probably involved in virulence (PubMed:19103776, Ref.3). The bacteria may break down various host compounds or host cell membranes through the coordinated action of phospholipase C and phosphocholine phosphatase. The final consequence of the action of these enzymes is an increase of the free choline concentration, which may promote the pathogenicity of P.aeruginosa (Ref.3).[5] [6] Publication Abstract from PubMedPseudomonas aeruginosa is an opportunistic Gram-negative pathogen. It colonizes different tissues by the utilization of diverse mechanisms. One of these may involve the breakdown of the host cell membrane through the sequential action of hemolytic phospholipase C and phosphorylcholine phosphatase (PchP). The action of hemolytic phospholipase C on phosphatidylcholine produces phosphorylcholine, which is hydrolyzed to choline (Cho) and inorganic phosphate by PchP. The available biochemical data on this enzyme demonstrate the involvement of two Cho-binding sites in the catalytic cycle and in enzyme regulation. The crystal structure of P. aeruginosa PchP has been determined. It folds into three structural domains. The first domain harbors all the residues involved in catalysis and is well conserved among the haloacid dehalogenase superfamily of proteins. The second domain is characteristic of PchP and is involved in the recognition of the Cho moiety of the substrate. The third domain stabilizes the relative position of the other two. Fortuitously, the crystal structure of PchP captures molecules of Bistris (2-[bis(2-hydroxyethyl)amino]-2-(hydroxymethyl)propane-1,3-diol) at the active site and at an additional site. This represents two catalytically relevant complexes with just one or two inhibitory Bistris molecules and provides the basis of the PchP function and regulation. Site-directed mutagenesis along with biochemical experiments corroborates the structural observations and demonstrates the interplay between different sites for Cho recognition and inhibition. The structural comparison of PchP with other phosphatases of the haloacid dehalogenase family provides a three-dimensional picture of the conserved catalytic cycle and the structural basis for the recognition of the diverse substrate molecules. The Structural Domains of Pseudomonas aeruginosa Phosphorylcholine Phosphatase Cooperate in Substrate Hydrolysis: 3D Structure and Enzymatic Mechanism.,Infantes L, Otero LH, Beassoni PR, Boetsch C, Lisa AT, Domenech CE, Albert A J Mol Biol. 2012 Aug 21. pii: S0022-2836(12)00608-0. doi:, 10.1016/j.jmb.2012.07.024. PMID:22922065[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||||
