title: A high-molecular-mass cell-surface protein from Lactobacillus reuteri 1063 adheres to mucus components.
abstract: A gene from Lactobacillus reuteri 1063 encoding a cell-surface protein, designated Mub, that adheres to mucus components in vitro has been cloned and sequenced. The deduced amino acid sequence of Mub (358 kDa) shows the presence of 14 approximately 200 aa repeats and features typical for other cell-surface proteins of Gram-positive bacteria. Fusion proteins consisting of different repeats of Mub and the maltose-binding protein (MBP) were produced. These proteins adhered to pig mucus components, with molecular masses ranging from <0.1 to >2 MDa, to pig gastric mucin and to hen intestinal mucus. The binding of Mub to mucus components occurred in the pH range 3-7.4, with maximum binding at pH 4-5 and could be partly inhibited by the glycoprotein fetuin. Affinity-purified antibodies against recombinant Mub were used in immunofluorescence microscopy to demonstrate the presence of Mub on the cell surface of strain 1063. By using the antibodies in a Western blot analysis, Mub could also be detected in the growth medium. The results implicate Mub as a cell-surface protein that is involved in Lactobacillus interactions with mucin and in colonization of the digestive tract.
authors.affiliation: Department of Microbiology, Swedish University of Agricultural Sciences, Box 7025, S-750 07 Uppsala, Sweden1.
authors.forename: Stefan
authors.initials: S
authors.lastname: Roos
authors.affiliation: Department of Microbiology, Swedish University of Agricultural Sciences, Box 7025, S-750 07 Uppsala, Sweden1.
authors.forename: Hans
authors.initials: H
authors.lastname: Jonsson
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002645:Chickens; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004064:Digestive System / Q000382:microbiology; D005798:Genes, Bacterial; D066298:In Vitro Techniques; D007778:Lactobacillus / Q000235:genetics / Q000378:metabolism*; D058619:Maltose-Binding Proteins; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009093:Mucus / Q000382:microbiology*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013552:Swine
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D058619:Maltose-Binding Proteins; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins