title: Variability of the Vaa cytoadhesin genes in clinical isolates of Mycoplasma hominis.
abstract: The Mycoplasma hominis vaa gene encodes a highly variable surface antigen involved in adhesion to host cells. We studied 15 clinical isolates of Mycoplasma hominis with three types of the vaa gene. These vaa versions determine various forms of Vaa protein, which are characterized by different quantity and structure of homologous replaceable cassettes. Each cassette contains heptad repeats and sites for adherence. The differences on single nucleotides were observed in the primary sequences of the homologous modules of the vaa gene. A high frequency of nucleotide replacements in V module of the vaa gene (first and/or second position in codon) was determined. This region with various clusters of direct and indirect repeats of nucleotide sequences is incorporated into the area of the vaa gene. Amino-acid sequences corresponding to the hyper-variable region of the vaa gene are associated with the sections of coiled-coils and loops of Vaa. These bacterial regions involved in interaction with the host cell membranes could yield useful indications for more insights into the mechanism of mycoplasma persistence in humans.
authors.affiliation: Kazan Institute of Biochemistry and Biophysics, Kazan, Russia.
authors.forename: Vladislav M
authors.initials: VM
authors.lastname: Chernov
authors.forename: Oleg V
authors.initials: OV
authors.lastname: Gorshkov
authors.forename: Olga A
authors.initials: OA
authors.lastname: Chernova
authors.forename: Natalia B
authors.initials: NB
authors.lastname: Baranova
authors.forename: Tatiana A
authors.initials: TA
authors.lastname: Akopian
authors.forename: Maxim V
authors.initials: MV
authors.lastname: Trushin
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics*; D000940:Antigenic Variation; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D014644:Genetic Variation; D006801:Humans; D008958:Models, Molecular; D009175:Mycoplasma Infections / Q000382:microbiology*; D019535:Mycoplasma hominis / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012091:Repetitive Sequences, Nucleic Acid; D017422:Sequence Analysis, DNA
chemical_list: D018829:Adhesins, Bacterial; D004269:DNA, Bacterial; C115186:Vaa protein, Mycoplasma hominis