title: In Mycoplasma hominis the OppA-mediated cytoadhesion depends on its ATPase activity.
abstract: BACKGROUND
  In Mycoplasma hominis, a facultative human pathogen of the human genital tract, OppA, the substrate-binding domain of the oligopeptide permease, is a multifunctional protein involved in nutrition uptake, cytoadhesion and hydrolysis of extracellular ATP.
  
  
  RESULTS
  To map the function-related protein regions the ATPase activity and adhesive behavior of OppA mutants were analyzed. Mutations of the Walker BA motifs resulted in an inhibition of up to 8% of the OppA ATPase activity, whereas deletion of the N-terminal CS1 or the CS2 region, structural motifs that are conserved in bacterial OppA proteins, reduced ATPase activity to 60% and deletion of CS3, the third conserved region adjacent to the Walker B motif led to a reduction to 42% ATPase activity. Interestingly, adhesion of the OppA mutants to immobilized HeLa cells demonstrated that two distal regions are mainly involved in adherence of OppA: the CS1 region, deletion of which led to 35% of the cytoadhesion, and the Walker BA with the adjacent upstream region CS3, deletion of which led to 25% of the cytoadhesion. The influence of the ATPase activity on the adherence of M. hominis to HeLa cells was confirmed by the use of ATPase inhibitors which reduced mycoplasmal cytoadhesion to 50%.
  
  
  CONCLUSIONS
  These findings suggest that the OppA-mediated cytoadherence of Mycoplasma hominis depends on both, the topology of the neighbouring CS1 and ATPase domain regions and the functionality of the ecto-ATPase activity in addition.
authors.affiliation: Institute of Medical Microbiology and Hospital Hygiene, Heinrich-Heine-University Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany.
authors.forename: Miriam
authors.initials: M
authors.lastname: Hopfe
authors.forename: Theresa
authors.initials: T
authors.lastname: Dahlmanns
authors.forename: Birgit
authors.initials: B
authors.lastname: Henrich
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008074:Lipoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009175:Mycoplasma Infections / Q000382:microbiology*; D019535:Mycoplasma hominis / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D017434:Protein Structure, Tertiary
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D008074:Lipoproteins; C046506:oligopeptide-binding protein, bacteria; D000251:Adenosine Triphosphatases