title: Novel families of putative protein kinases in bacteria and archaea: evolution of the "eukaryotic" protein kinase superfamily.
abstract: The central role of serine/threonine and tyrosine protein kinases in signal transduction and cellular regulation in eukaryotes is well established and widely documented. Considerably less is known about the prevalence and role of these protein kinases in bacteria and archaea. In order to examine the evolutionary origins of the eukaryotic-type protein kinase (ePK) superfamily, we conducted an extensive analysis of the proteins encoded by the completely sequenced bacterial and archaeal genomes. We detected five distinct families of known and predicted putative protein kinases with representatives in bacteria and archaea that share a common ancestry with the eukaryotic protein kinases. Four of these protein families have not been identified previously as protein kinases. From the phylogenetic distribution of these families, we infer the existence of an ancestral protein kinase(s) prior to the divergence of eukaryotes, bacteria, and archaea.
authors.affiliation: National Center for Biotechnology Information (NCBI), National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894 USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Leonard
authors.forename: L
authors.initials: L
authors.lastname: Aravind
authors.forename: E V
authors.initials: EV
authors.lastname: Koonin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001105:Archaea / Q000201:enzymology* / Q000235:genetics; D001419:Bacteria / Q000201:enzymology* / Q000235:genetics; D017124:Conserved Sequence; D005057:Eukaryotic Cells / Q000201:enzymology*; D019143:Evolution, Molecular; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D011505:Protein-Tyrosine Kinases / Q000737:chemistry / Q000235:genetics / Q000502:physiology
chemical_list: D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases