title: Biochemical examination of the potential eukaryotic-type protein kinase genes in the complete genome of the unicellular Cyanobacterium synechocystis sp. PCC 6803.
abstract: The complete genome of the unicellular motile cyanobacterium Synechocystis sp. PCC 6803 harbors seven putative genes for a subfamily Pkn2 of the eukaryotic-type (or "Hanks-type") protein kinase. Previously, SpkA and SpkB were shown to have protein kinase activity and to be required for cell motility. Here, the other five genes were examined. These genes, except for spkG (slr0152), were successfully expressed in Escherichia coli. Eukaryotic-type protein kinase activity of the expressed SpkC (Slr0599), SpkD (S110776) and SpkF (Slr1225) was demonstrated as autophosphorylation and phosphorylation of the general substrate proteins. SpkE (Slr1443) did not show any activity, a finding consistent with its lack of several key amino acid residues in its kinase motif. Gene-disrupted mutants showed no discernible defect in phenotype except that spkD was apparently essential for survival.
authors.affiliation: Department of Life Sciences, The University of Tokyo, Meguro, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Kamei
authors.forename: Takashi
authors.initials: T
authors.lastname: Yuasa
authors.forename: Xiaoxing
authors.initials: X
authors.lastname: Geng
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ikeuchi
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D000458:Cyanobacteria / Q000201:enzymology*; D004926:Escherichia coli / Q000201:enzymology; D015870:Gene Expression; D016680:Genome, Bacterial; D008969:Molecular Sequence Data; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins; C093969:Pkn2 kinase; D017346:Protein Serine-Threonine Kinases