title: [Ribonucleolytic activity of mycoplasmas].
abstract: Mycoplasmas are incapable of de novo synthesis of nucleotides and must therefore secrete nucleases in order to replenish the pool of nucleic acid precursors. The nucleolytic activity of mycoplasmas is an important factor in their pathogenicity. Bacterial ribonucleases (RNases) may produce a broad spectrum of biological effects, including antiviral and antitumor activity. Mycoplasma RNases are therefore of interest. In the present work, capacity of Acholeplasma laidlawii and Mycoplasma hominis for RNase synthesis and secretion was studied. During the stationary growth phase, these organisms were found to synthesize Mg(2+)-dependent RNases, with their highest activity detected outside the cells. Localization of A. laidlawii RNases was determined: almost 90% of the RNase activity was found to be associated with the membrane vesicles. Bioinformational analysis revealed homology between the nucleotide sequences of 14 Bacillus subtilis genes encoding the products with RNase activity and the genes of the mycoplasmas under study. Amino acid sequences of 4 A. laidlawii proteins with ribonuclease activity and the Bsn RNase was also established.
authors.forename: O N
authors.initials: ON
authors.lastname: Il'inskaya
authors.forename: Yu V
authors.initials: YV
authors.lastname: Sokurenko
authors.forename: V V
authors.initials: VV
authors.lastname: Ul'yanova
authors.forename: V I
authors.initials: VI
authors.lastname: Vershinina
authors.forename: P V
authors.initials: PV
authors.lastname: Zelenikhin
authors.forename: A I
authors.initials: AI
authors.lastname: Kolpakov
authors.forename: E S
authors.initials: ES
authors.lastname: Medvedeva
authors.forename: N B
authors.initials: NB
authors.lastname: Baranova
authors.forename: M N
authors.initials: MN
authors.lastname: Davydova
authors.forename: A A
authors.initials: AA
authors.lastname: Muzykantov
authors.forename: O A
authors.initials: OA
authors.lastname: Chernova
authors.forename: V M
authors.initials: VM
authors.lastname: Chernov
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics; D008274:Magnesium / Q000378:metabolism; D009174:Mycoplasma / Q000254:growth & development / Q000378:metabolism*; D019535:Mycoplasma hominis / Q000254:growth & development / Q000378:metabolism; D012260:Ribonucleases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
chemical_list: D012260:Ribonucleases; D008274:Magnesium