Regulation of methylthioribose kinase by methionine in Klebsiella pneumoniae.
5-Methylthioribose (MTR) kinase catalyses a key step in the recycling of methionine from 5'-methylthioadenosine, a co-product of polyamine biosynthesis, in Klebsiella pneumoniae. In defined medium lacking methionine, K. pneumoniae exhibits abundant MTR kinase activity. When the bacterium is transferred to a medium containing 10 mM-methionine, the specific activity of MTR kinase decreases in a fashion consistent with repression of new enzyme synthesis and dilution of existing enzyme by cell division. The specific activity of methionine synthase decreases to a similar degree under the same conditions. In Escherichia coli and Salmonella typhimurium, the gene for methionine synthase is co-ordinately controlled as part of the methionine regulon. Taken together, our results indicate that a methionine regulon may function in K. pneumoniae and that expression of MTR kinase may be under its control.
Tower
P A
PA
Medical Research Service, Department of Veterans Affairs Medical Center, Portland, Oregon 97201.
Alexander
D B
DB
Johnson
L L
LL
Riscoe
M K
MK
D004305:Dose-Response Relationship, Drug; D004794:Enzyme Repression; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D007711:Klebsiella pneumoniae / Q000378:metabolism*; D008715:Methionine / Q000378:metabolism / Q000494:pharmacology*; D008954:Models, Biological; D010770:Phosphotransferases / Q000096:biosynthesis*; D017853:Phosphotransferases (Alcohol Group Acceptor)
D008715:Methionine; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C021787:5-methylthioribose kinase