A novel protein kinase that controls carbon catabolite repression in bacteria.
HPr(Ser) kinase is the sensor in a multicomponent phosphorelay system that controls catabolite repression, sugar transport and carbon metabolism in gram-positive bacteria. Unlike most other protein kinases, it recognizes the tertiary structure in its target protein, HPr, a phosphocarrier protein of the bacterial phosphotransferase system and a transcriptional cofactor controlling the phenomenon of catabolite repression. We have identified the gene (ptsK) encoding this serine/threonine protein kinase and characterized the purified protein product. Orthologues of PtsK have been identified only in bacteria. These proteins constitute a novel family unrelated to other previously characterized protein phosphorylating enzymes. The Bacillus subtilis kinase is shown to be allosterically activated by metabolites such as fructose 1,6-bisphosphate and inhibited by inorganic phosphate. In contrast to wild-type B. subtilis, the ptsK mutant is insensitive to transcriptional regulation by catabolite repression. The reported results advance our understanding of phosphorylation-dependent carbon control mechanisms in Gram-positive bacteria.
Reizer
J
J
Department of Biology, University of California at San Diego, La Jolla 92093-0116, USA.
Hoischen
C
C
Titgemeyer
F
F
Rivolta
C
C
Rabus
R
R
Stülke
J
J
Karamata
D
D
Saier
M H
MH
Hillen
W
W
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000494:Allosteric Regulation / Q000502:physiology; D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry; D004789:Enzyme Activation / Q000502:physiology; D004791:Enzyme Inhibitors; D004926:Escherichia coli / Q000235:genetics; D005635:Fructosediphosphates / Q000494:pharmacology; D016680:Genome, Bacterial; D008969:Molecular Sequence Data; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000378:metabolism; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000737:chemistry*; D017346:Protein Serine-Threonine Kinases; D011994:Recombinant Proteins / Q000737:chemistry; D016415:Sequence Alignment; D017421:Sequence Analysis
D001426:Bacterial Proteins; D004791:Enzyme Inhibitors; D005635:Fructosediphosphates; D047428:Protein Kinase Inhibitors; D011994:Recombinant Proteins; D000255:Adenosine Triphosphate; D011494:Protein Kinases; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C030182:phosphocarrier protein HPr; C110847:HPr kinase; D017346:Protein Serine-Threonine Kinases; C029063:fructose-1,6-diphosphate