Characterization of a novel bacterial arginine kinase from Desulfotalea psychrophila.
Phosphagen kinases are found throughout the animal kingdom and catalyze the transfer of a high-energy gamma phosphoryl-group from ATP to a guanidino group on a suitable acceptor molecule such as creatine or arginine. Recent genome sequencing efforts in several proteobacteria, including Desulfotalea psychrophila LSv54, Myxococcus xanthus, Sulfurovum sp. NBC37-1, and Moritella sp. PE36 have revealed what appears to be a phosphagen kinase homolog present in their genomes. Based on sequence comparisons these putative homologs bear a strong resemblance to arginine kinases found in many invertebrates and some protozoa. We describe here a biochemical characterization of one of these homologs from D. psychrophila expressed in E. coli that confirms its ability to reversibly catalyze phosphoryl transfer from ATP to arginine. A phylogenetic analysis suggests that these bacteria homologs are not widely distributed in proteobacteria species. They appear more related to protozoan arginine kinases than to similar proteins seen in some Gram-positive bacteria that share key catalytic residues but encode protein tyrosine kinases. This raises the possibility of horizontal gene transfer as a likely origin of the bacterial arginine kinases.
Andrews
Logan D
LD
Department of Biology, The College of Wooster, Wooster, OH 44691, USA.
Graham
James
J
Snider
Mark J
MJ
Fraga
Dean
D
D000595:Amino Acid Sequence; D000818:Animals; D001122:Arginine Kinase / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D020564:Deltaproteobacteria / Q000201:enzymology*; D056890:Eukaryota / Q000201:enzymology; D007700:Kinetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012343:RNA, Transfer / Q000378:metabolism; D016415:Sequence Alignment
D001426:Bacterial Proteins; D012343:RNA, Transfer; D001122:Arginine Kinase