title: Characterization of the gene encoding the protective paracrystalline-surface-layer protein of Rickettsia prowazekii: presence of a truncated identical homolog in Rickettsia typhi.
abstract: The DNA sequence of the gene encoding the protective surface protein antigen (SPA) of Rickettsia prowazekii has been determined. The open reading frame of 4836 nucleotides with promoter and ribosome-binding site is present on a 10.1-kilobase EcoRI fragment. The encoded carboxyl terminus of the 169-kDa protein contains a potential transmembrane region and hydrophilic regions with many lysine and arginine residues potentially accessible to proteolytic cleavage. Because the rickettsia-derived SPA has an estimated molecular mass of only 120 kDa and does not contain several predicted large carboxyl-region CNBr fragments, the SPA product appears to be processed by the rickettsiae. Eight other CNBr fragments were identical in sequence to those predicted from the encoded gene. A complementary 8.7-kilobase EcoRI fragment of Rickettsia typhi DNA was cloned. This fragment lacked a 1433-base-pair region that included the promoter, ribosome-binding site, and the initial 1162 base pairs of the open reading frame encoding the R. prowazekii SPA but had a 3674-base-pair region identical with the remainder of the R. prowazekii SPA gene sequence.
authors.affiliation: Infectious Diseases Department, Naval Medical Research Institute, Bethesda, MD 20814-5055.
authors.forename: M
authors.initials: M
authors.lastname: Carl
authors.forename: M E
authors.initials: ME
authors.lastname: Dobson
authors.forename: W M
authors.initials: WM
authors.lastname: Ching
authors.forename: G A
authors.initials: GA
authors.lastname: Dasch
mesh_terms: D000595:Amino Acid Sequence; D000954:Antigens, Surface / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D016133:Polymerase Chain Reaction; D011487:Protein Conformation; D015183:Restriction Mapping; D012283:Rickettsia prowazekii / Q000235:genetics*; D012286:Rickettsia typhi / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
chemical_list: D000954:Antigens, Surface; D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial