title: Molecular cloning and characterization of Dr-II, a nonfimbrial adhesin-I-like adhesin isolated from gestational pyelonephritis-associated Escherichia coli that binds to decay-accelerating factor.
abstract: Bacterial adhesins play an important role in the colonization of the human urogenital tract. Escherichia coli Dr family adhesins have been found to be frequently expressed in strains associated with pyelonephritis in pregnant females. The tissue receptor for known Dr adhesins has been localized to the short consensus repeat-3 (SCR-3) domain of decay accelerating factor (DAF), a complement regulatory protein. In this report, we identified and cloned draE2, a gene encoding a novel 17-kDa DAF-binding adhesin, Dr-II, from a strain of E. coli associated with acute gestational pyelonephritis. Despite the significant sequence diversity between Dr-II and Dr family adhesins, the receptor of Dr-II was found to be the SCR-3 domain of DAF. Sequence analysis of the 186-amino-acid Dr-II open reading frame revealed significant diversity from other members of the Dr adhesin family, including Dr, AFA-I, AFA-III, and F1845, but only an 8-amino-acid difference in sequence from that of the 17-kDa nonfimbrial adhesin NFA-I of unknown receptor specificity. N-terminal peptide sequencing of the purified adhesin confirmed the identity of the open reading frame and indicated cleavage of a 28-amino-acid signal peptide. Antibodies raised against purified Dr-II adhesin exhibited little or no cross-reactivity to Dr adhesin. Characterization of the biological properties demonstrated that like the Dr adhesins, Dr-II was associated with the ability of E. coli to bind to tubular basement membranes and Bowman's capsule and to be internalized into HeLa cells.
authors.affiliation: Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston 77555, USA.
authors.forename: T Q
authors.initials: TQ
authors.lastname: Pham
authors.forename: P
authors.initials: P
authors.lastname: Goluszko
authors.forename: V
authors.initials: V
authors.lastname: Popov
authors.forename: S
authors.initials: S
authors.lastname: Nowicki
authors.forename: B J
authors.initials: BJ
authors.lastname: Nowicki
mesh_terms: D018830:Adhesins, Escherichia coli / Q000737:chemistry / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D018958:CD55 Antigens / Q000378:metabolism*; D003001:Cloning, Molecular; D003429:Cross Reactions; D004926:Escherichia coli / Q000235:genetics* / Q000276:immunology / Q000648:ultrastructure; D005260:Female; D006046:Gold; D006367:HeLa Cells / Q000166:cytology / Q000378:metabolism / Q000382:microbiology; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000378:metabolism / Q000382:microbiology; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D009876:Operon; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000382:microbiology*; D011485:Protein Binding; D011704:Pyelonephritis / Q000382:microbiology*; D011971:Receptors, Immunologic / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D018830:Adhesins, Escherichia coli; D018958:CD55 Antigens; D011971:Receptors, Immunologic; C108514:draE2 protein, E coli; D006046:Gold