title: SdrI of Staphylococcus saprophyticus is a multifunctional protein: localization of the fibronectin-binding site.
abstract: Staphylococcus saprophyticus, an important cause of urinary tract infections in young women, expresses the surface protein SdrI, a member of the serine-aspartate repeat (SD) protein family. Here we analyse the fibronectin-binding ability of SdrI, as S. saprophyticus is known to bind fibronectin and there is no known SD protein with this function. This protein does not contain the binding motif typical for fibronectin-binding proteins. Using recombinant fragments of SdrI, we localized the binding domain in the A region and show that SdrI bound to the N-terminal 30-kDa fragment of fibronectin. The fibronectin-binding function was shown in the natural host using an SdrI knockout mutant that showed decreased binding to fibronectin compared with wild-type strain 7108.
authors.affiliation: Institut für Hygiene und Mikrobiologie, Abteilung für Medizinische Mikrobiologie, Ruhr-Universität Bochum, Bochum, Germany. tuerkan.sakinc@rub.de
authors.forename: Türkân
authors.initials: T
authors.lastname: Sakinç
authors.forename: Britta
authors.initials: B
authors.lastname: Kleine
authors.forename: Nadine
authors.initials: N
authors.lastname: Michalski
authors.forename: Martin
authors.initials: M
authors.lastname: Kaase
authors.forename: Sören G
authors.initials: SG
authors.lastname: Gatermann
mesh_terms: D018829:Adhesins, Bacterial / Q000737:chemistry / Q000378:metabolism*; D020816:Amino Acid Motifs; D000818:Animals; D001665:Binding Sites; D005260:Female; D005353:Fibronectins / Q000737:chemistry / Q000378:metabolism*; D055786:Gene Knockout Techniques; D005798:Genes, Bacterial; D054884:Host-Pathogen Interactions; D006801:Humans; D011485:Protein Binding; D011817:Rabbits; D011994:Recombinant Proteins / Q000378:metabolism; D013203:Staphylococcal Infections / Q000382:microbiology; D013210:Staphylococcus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014552:Urinary Tract Infections / Q000382:microbiology
chemical_list: D018829:Adhesins, Bacterial; D005353:Fibronectins; C509820:MSCRAMM proteins, Staphylococcus; D011994:Recombinant Proteins