Molecular design of Mycoplasma hominis Vaa adhesin.

T Boesen, N U Fedosova, M Kjeldgaard, S Birkelund, G Christiansen

Journal: Protein science : a publication of the Protein Society 2002;10(12):2577-86

PMID: 11714926

Free Full Text on PubMed Central View on PubMed

Abstract

The variable adherence-associated (Vaa) adhesin of the opportunistic human pathogen Mycoplasma hominis is a surface-exposed, membrane-associated protein involved in the attachment of the bacterium to host cells. The molecular masses of recombinant 1 and 2 cassette forms of the protein determined by a light-scattering (LS) method were 23.9 kD and 36.5 kD, respectively, and corresponded to their monomeric forms. Circular dichroism (CD) spectroscopy of the full-length forms indicated that the Vaa protein has an alpha-helical content of approximately 80%. Sequence analysis indicates the presence of coiled-coil domains in both the conserved N-terminal and antigenic variable C-terminal part of the Vaa adhesin. Experimental results obtained with recombinant proteins corresponding to the N- or C-terminal parts of the shortest one-cassette form of the protein were consistent with the hypothesis of two distinct coiled-coil regions. The one-cassette Vaa monomer appears to be an elongated protein with a axial shape ratio of 1:10. Analysis of a two-cassette Vaa type reveals a similar axial shape ratio. The results are interpreted in terms of the topological organization of the Vaa protein indicating the localization of the adherence-mediating structure.

Address: Department of Medical Microbiology and Immunology, University of Aarhus, DK-8000 Aarhus C, Denmark. [email protected]

DOI: 10.1110/ps.ps.31901

Link outs

Free resources

Full Text Sources:

MeSH Terms: Adhesins, Bacterial, Amino Acid Sequence, Bacterial Proteins, Chromatography, Affinity, Circular Dichroism, Cloning, Molecular, Electrophoresis, Polyacrylamide Gel, Light, Membrane Proteins, Models, Molecular, Molecular Sequence Data, Mycoplasma hominis, Plasmids, Polymerase Chain Reaction, Protein Binding, Protein Structure, Secondary, Protein Structure, Tertiary, Recombinant Proteins, Scattering, Radiation, Software, Water