title: Cloning and sequencing of gene coding for a periplasmic 5.4 kDa peptide of the macronucleus-specific symbiont Holospora obtusa of the ciliate Paramecium caudatum.
abstract: We purified a 5.4 kDa peptide which is present in the intermediate and infectious form, but not in the reproductive form of a symbiotic bacterium Holospora obtusa of the ciliate Paramecium caudatum. Sequencing of its gene revealed that it encodes a peptide composed of 49 amino acids, and that the peptide is preceded by a putative signal peptide of 19 amino acids. We determined the transcription start point for the gene by primer extension analysis, indicating that the transcription starts with a G nucleotide located 33 nucleotides upstream from the translational initiation codon. Northern blot hybridization showed that the gene is highly expressed in the intermediate form, a transitional stage from the reproductive to infectious form of the bacterium. Immunoelectron microscopy with anti-5.4 kDa peptide antiserum revealed that the 5.4 kDa peptide is localized in the periplasm of the infectious form.
authors.affiliation: Department of Biological Sciences, Graduate School of Science, University of Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Dohra
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
authors.forename: M
authors.initials: M
authors.lastname: Fujishima
authors.forename: H
authors.initials: H
authors.lastname: Ishikawa
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D006090:Gram-Negative Bacteria / Q000235:genetics*; D008969:Molecular Sequence Data; D010247:Paramecium / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D013559:Symbiosis
chemical_list: D001426:Bacterial Proteins