title: Structural and Biochemical Analysis of Tyrosine Phosphatase Related to Biofilm Formation A (TpbA) from the Opportunistic Pathogen Pseudomonas aeruginosa PAO1.
abstract: Biofilms are important for cell communication and growth in most bacteria, and are responsible for a number of human clinical infections and diseases. TpbA (PA3885) is a dual specific tyrosine phosphatase (DUSP) that negatively regulates biofilm formation in the opportunistic pathogen Pseudomonas aeruginosa PAO1 by converting extracellular quorum sensing signals into internal gene cascade reactions that result in reduced biofilm formation. We have determined the three-dimensional crystal structure of wild-type TpbA from P. aeruginosa PAO1 in the phosphate-bound state and a TpbA (C132S) mutant with phosphotyrosine. Comparison between the phosphate-bound structure and the previously reported ligand-free TpbA structure reveals the extent of conformational changes that occur upon substrate binding. The largest changes occur in the functional loops that define the substrate binding site, including the PTP, general acid and α4-α5 loops. We further show that TpbA efficiently catalyzes the hydrolysis of two phosphotyrosine peptides derived from the periplasmic domain of TpbB (YfiN, PA1120), with a strong preference for dephosphorylating Tyr48 over Tyr62. This work adds to the small repertoire of DUSP structures in both the ligand-free and ligand-bound states, and provides a starting point for further study of the role of TpbA in biofilm formation.
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China; College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China; College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Li
authors.affiliation: College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Yang
authors.affiliation: College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Kan
authors.initials: K
authors.lastname: Li
authors.affiliation: College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Bai
authors.affiliation: College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Yueyang
authors.initials: Y
authors.lastname: Xu
authors.affiliation: College of Pharmacy, Nankai University, Tianjin, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Jin
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), College of Environmental Science and Engineering, Nankai University, Tianjin, China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China; College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Mark
authors.initials: M
authors.lastname: Bartlam
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018441:Biofilms; D006868:Hydrolysis; D008024:Ligands; D008954:Models, Biological; D008958:Models, Molecular; D009154:Mutation; D010766:Phosphorylation; D011485:Protein Binding; D011487:Protein Conformation; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D011994:Recombinant Proteins; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D008024:Ligands; D011994:Recombinant Proteins; D017027:Protein Tyrosine Phosphatases