A gene encoding a protein serine/threonine kinase is required for normal development of M. xanthus, a gram-negative bacterium.
PCR reactions were carried out on the genomic DNA of M. xanthus, a soil bacterium capable of differentiation to form fruiting bodies, using oligonucleotides representing highly conserved regions of eukaryotic protein serine/threonine kinases. A gene (pkn1) thus cloned contains an ORF of 693 amino acid residues whose amino-terminal domain shows significant sequence similarity with the catalytic domain of eukaryotic protein serine/threonine kinases. The pkn1 gene was overexpressed in E. coli, and the gene product has been found to be autophosphorylated at both serine and threonine residues. The expression of pkn1 is developmentally regulated to start immediately before spore formation. When pkn1 is deleted, differentiation starts prematurely, resulting in poor spore production. These results indicate that the protein serine/threonine kinase plays an important role in the onset of proper differentiation.
Muñoz-Dorado
J
J
Department of Biochemistry, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School at Rutgers, Piscataway 08854.
Inouye
S
S
Inouye
M
M
D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016941:Myxococcus xanthus / Q000201:enzymology / Q000235:genetics* / Q000502:physiology; D009838:Oligodeoxyribonucleotides; D016366:Open Reading Frames; D010641:Phenotype; D010750:Phosphoproteins / Q000302:isolation & purification / Q000378:metabolism; D010761:Phosphorus Radioisotopes; D016133:Polymerase Chain Reaction / Q000379:methods; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D011994:Recombinant Proteins / Q000378:metabolism; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D013171:Spores, Bacterial; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D004269:DNA, Bacterial; D009838:Oligodeoxyribonucleotides; D010750:Phosphoproteins; D010761:Phosphorus Radioisotopes; D011994:Recombinant Proteins; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D001616:beta-Galactosidase