Journal Article

Biochemical Examination of the Potential Eukaryotic-type Protein Kinase Genes in the Complete Genome of the Unicellular Cyanobacterium <i>Synechocystis</i> sp. PCC 6803

Ayako Kamei, Takashi Yuasa, Xiaoxing Geng and Masahiko Ikeuchi

in DNA Research

Published on behalf of Kazusa DNA Research Institute

Volume 9, issue 3, pages 71-78
Published in print January 2002 | ISSN: 1340-2838
Published online January 2002 | e-ISSN: 1756-1663 | DOI:

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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 (Sll0776) 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.

Keywords: autophosphorylation; cyanobacterium; motility; phototaxis; pkn2; protein kinase; signal transduction

Journal Article.  0 words. 

Subjects: Genetics and Genomics

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