title: Structure-function aspects of the Porphyromonas gingivalis tyrosine kinase Ptk1.
abstract: The development of synergistically pathogenic communities of Porphyromonas gingivalis and Streptococcus gordonii is controlled by a tyrosine-phosphorylation-dependent signaling pathway in P. gingivalis. The Ptk1 bacterial tyrosine (BY) kinase of P. gingivalis is required for maximal community development and for the production of extracellular polysaccharide. We show that the consensus BY kinase Walker A and B domains, the RK cluster, and the YC domain of Ptk1 are necessary for autophosphorylation and for substrate phosphorylation. Mass spectrometry showed that six tyrosine residues in a 16-amino-acid C-terminal region were phosphorylated in recombinant (r) Ptk1. Complementation of a ptk1 mutant with the wild-type ptk1 allele in trans restored community development between P. gingivalis and S. gordonii, and extracellular polysaccharide production by P. gingivalis. In contrast, complementation of Δptk1 with ptk1 containing a mutation in the Walker A domain failed to restore community development or extracellular polysaccharide production. rPtk1 was capable of phosphorylating the tyrosine phosphatase Ltp1 and the transcriptional regulator CdhR, both of which are involved in the development of P. gingivalis communities with S. gordonii.
authors: Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, USA.|State Key Laboratory of Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
authors: C
authors: C
authors: Liu
authors: Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, USA.
authors: D P
authors: DP
authors: Miller
authors: Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, USA.|Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
authors: Y
authors: Y
authors: Wang
authors: Department of Medicine, School of Medicine, University of Louisville, Louisville, KY, USA.
authors: M
authors: M
authors: Merchant
authors: Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, USA.
authors: R J
authors: RJ
authors: Lamont
mesh_terms: D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology; D018441:Biofilms / Q000254:growth & development; D015964:Gene Expression Regulation, Bacterial; D056265:Microbial Interactions; D009154:Mutation; D010766:Phosphorylation; D016966:Porphyromonas gingivalis / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000737:chemistry* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction; D054773:Streptococcus gordonii / Q000235:genetics / Q000502:physiology; D013329:Structure-Activity Relationship
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D011505:Protein-Tyrosine Kinases
keywords: biofilms; extracellular polysaccharide; periodontal disease