title: Characterization of adhesion threads of Deinococcus geothermalis as type IV pili.
abstract: Deinococcus geothermalis E50051 forms tenuous biofilms on paper machine surfaces. Field emission electron microscopy analysis revealed peritrichous appendages which mediated cell-to-surface and cell-to-cell interactions but were absent in planktonically grown cells. The major protein component of the extracellular extract of D. geothermalis had an N-terminal sequence similar to the fimbrial protein pilin annotated in the D. geothermalis DSM 11300 draft sequence. It also showed similarity to the type IV pilin sequence of D. radiodurans and several gram-negative pathogenic bacteria. Other proteins in the extract had N-terminal sequences identical to D. geothermalis proteins with conservative motifs for serine proteases, metallophosphoesterases, and proteins whose function is unknown. Periodic acid-Schiff staining for carbohydrates indicated that these extracellular proteins may be glycosylated. A further confirmation for the presence of glycoconjugates on the cell surface was obtained by confocal laser scanning imaging of living D. geothermalis cells stained with Amaranthus caudatus lectin, which specifically binds to galactose residues. The results indicate that the thread-like appendages of D. geothermalis E50051 are glycosylated type IV pili, bacterial attachment organelles which have thus far not been described for the genus Deinococcus.
authors.affiliation: Bioprocess Engineering Laboratory, Department of Process and Environmental Engineering, University of Oulu, P.O. Box 4300, FI-90014 Oulun Yliopisto, Finland.
authors.forename: C
authors.initials: C
authors.lastname: Saarimaa
authors.forename: M
authors.initials: M
authors.lastname: Peltola
authors.forename: M
authors.initials: M
authors.lastname: Raulio
authors.forename: T R
authors.initials: TR
authors.lastname: Neu
authors.forename: M S
authors.initials: MS
authors.lastname: Salkinoja-Salonen
authors.forename: P
authors.initials: P
authors.lastname: Neubauer
mesh_terms: D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification; D034301:Deinococcus / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure; D004591:Electrophoresis, Polyacrylamide Gel; D036781:Fimbriae Proteins / Q000737:chemistry / Q000235:genetics; D010861:Fimbriae, Bacterial / Q000737:chemistry / Q000648:ultrastructure*; D006001:Glycoconjugates / Q000032:analysis; D006031:Glycosylation; D045726:Metalloproteases / Q000737:chemistry / Q000235:genetics; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D037121:Plant Lectins / Q000378:metabolism; D011485:Protein Binding; D054788:Ribosome Inactivating Proteins; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics; D013194:Staining and Labeling
chemical_list: D001426:Bacterial Proteins; D006001:Glycoconjugates; D037121:Plant Lectins; C050600:Sambucus nigra lectins; D036781:Fimbriae Proteins; D054788:Ribosome Inactivating Proteins; D045726:Metalloproteases; D012697:Serine Endopeptidases