title: Unique monocistronic operon (ptsH) in Mycoplasma capricolum encoding the phosphocarrier protein, HPr, of the phosphoenolpyruvate:sugar phosphotransferase system. Cloning, sequencing, and characterization of ptsH.
abstract: The region of the genome of Mycoplasma capricolum encompassing the gene (ptsH) encoding HPr, a general energy-coupling protein of the phosphoenolpyruvate:sugar phosphotransferase system, was cloned and sequenced. Examination of the sequence revealed a unique arrangement of the ptsH gene. In all other bacterial species characterized thus far, the ptsH gene is part of a polycistronic operon that includes the gene (ptsI) encoding Enzyme I of the phosphoenolpyruvate:sugar phosphotransferase system; the M. capricolum ptsH gene is part of a monocistronic operon that is situated between two open reading frames unrelated to phosphoenolpyruvate:sugar phosphotransferase system function. The gene immediately upstream of ptsH codes for a helicase, and the open reading frame immediately downstream of ptsH, although not homologous to any previously identified protein, contains a signature sequence characteristic of [C-5] cytosine-specific DNA methylases. The product of the ptsH gene has characteristics similar to the HPr protein produced by Gram-positive organisms: it has a greater sequence similarity to HPrs of Gram-positive bacteria than to those of Gram-negative organisms, it is phosphorylated by a protein kinase derived from Gram-positive organisms, and it complements sugar phosphorylation activity in Gram-positive extracts. The high calculated isoelectric point (pI = 9.18) and the absence of glutamate residues in the C-terminal region distinguish the M. capricolum HPr from all previously described HPrs.
authors.affiliation: Laboratory of Biochemical Genetics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: P P
authors.initials: PP
authors.lastname: Zhu
authors.forename: J
authors.initials: J
authors.lastname: Reizer
authors.forename: A
authors.initials: A
authors.lastname: Reizer
authors.forename: A
authors.initials: A
authors.lastname: Peterkofsky
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial; D008969:Molecular Sequence Data; D009174:Mycoplasma / Q000201:enzymology / Q000235:genetics*; D009876:Operon; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics*; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C030182:phosphocarrier protein HPr