title: Interaction of Proteus mirabilis urease apoenzyme and accessory proteins identified with yeast two-hybrid technology.
abstract: Proteus mirabilis, a gram-negative bacterium associated with complicated urinary tract infections, produces a metalloenzyme urease which hydrolyzes urea to ammonia and carbon dioxide. The apourease is comprised of three structural subunits, UreA, UreB, and UreC, assembled as a homotrimer of individual UreABC heterotrimers (UreABC)(3). To become catalytically active, apourease acquires divalent nickel ions through a poorly understood process involving four accessory proteins, UreD, UreE, UreF, and UreG. While homologues of UreD, UreF, and UreG have been copurified with apourease, it remains unclear specifically how these polypeptides associate with the apourease or each other. To identify interactions among P. mirabilis accessory proteins, in vitro immunoprecipitation and in vivo yeast two-hybrid assays were employed. A complex containing accessory protein UreD and structural protein UreC was isolated by immunoprecipitation and characterized with immunoblots. This association occurs independently of coaccessory proteins UreE, UreF, and UreG and structural protein UreA. In a yeast two-hybrid screen, UreD was found to directly interact in vivo with coaccessory protein UreF. Unique homomultimeric interactions of UreD and UreF were also detected in vivo. To substantiate the study of urease proteins with a yeast two-hybrid assay, previously described UreE dimers and homomultimeric UreA interactions among apourease trimers were confirmed in vivo. Similarly, a known structural interaction involving UreA and UreC was also verified. This report suggests that in vivo, P. mirabilis UreD may be important for recruitment of UreF to the apourease and that crucial homomultimeric associations occur among these accessory proteins.
authors.affiliation: Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
authors.forename: S R
authors.initials: SR
authors.lastname: Heimer
authors.forename: H L
authors.initials: HL
authors.lastname: Mobley
mesh_terms: D000907:Antibodies, Bacterial; D001051:Apoenzymes / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics; D003001:Cloning, Molecular; D017931:DNA Primers; D015964:Gene Expression Regulation, Bacterial; D008956:Models, Chemical; D028044:Phosphate-Binding Proteins; D016133:Polymerase Chain Reaction; D011233:Precipitin Tests; D011485:Protein Binding; D011513:Proteus mirabilis / Q000201:enzymology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012697:Serine Endopeptidases / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D014510:Urease / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D000099160:LexA Repressor Protein
chemical_list: D000907:Antibodies, Bacterial; D001051:Apoenzymes; D001426:Bacterial Proteins; D002352:Carrier Proteins; D017931:DNA Primers; D028044:Phosphate-Binding Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D012697:Serine Endopeptidases; D014510:Urease; D000099160:LexA Repressor Protein; C086767:UreD protein, Bacteria; C090404:UreE protein, Bacteria; C101639:UreF protein, bacteria; C082270:ureG protein, Bacteria