title: Molecular cloning and characterization of nlpH, encoding a novel, surface-exposed, polymorphic, plasmid-encoded 33-kilodalton lipoprotein of Borrelia afzelii.
abstract: Borrelia burgdorferi sensu lato organisms, comprising B. burgdorferi sensu stricto, Borrelia afzelii, and Borrelia garinii, are tick-borne pathogens causing Lyme borreliosis in humans. To identify putative virulence determinants, a B. afzelii DNA library was screened for Congo red dye binding, a property associated with virulence in pathogenic bacteria. One clone was found to carry a 663-nucleotide-long open reading frame encoding a Congo red dye-binding protein with a calculated molecular mass of 25,660 Da. The amino acid sequence deduced from its nucleotide sequence was found to include a consensus bacterial lipidation site present at residues 15 to 18 (Leu-Ser-Gly-Cys). The lipoprotein nature was demonstrated by incorporation of radioactive palmitate; hence, this protein has been termed NlpH, for new lipoprotein H. NlpH is located on the surface of B. afzelii, and the nlpH gene is found on a circular plasmid. The nlpH gene is also found in B. burgdorferi sensu stricto and B. garinii. Immediately upstream of nlpH is located a smaller reading frame encoding a polypeptide containing the casein kinase II phosphorylation recognition sequence, (Ser/Thr)-X-Y-(Glu/Asp), repeated 10 times.
authors.affiliation: Department of Clinical Biochemistry, Statens Seruminstitut, Copenhagen, Denmark. theisen@biobase.dk
authors.forename: M
authors.initials: M
authors.lastname: Theisen
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D001898:Borrelia / Q000235:genetics* / Q000378:metabolism; D002451:Cell Compartmentation; D003001:Cloning, Molecular; D003224:Congo Red / Q000378:metabolism; D005798:Genes, Bacterial; D005838:Genotype; D006427:Hemin / Q000378:metabolism; D008074:Lipoproteins / Q000235:genetics*; D008565:Membrane Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010168:Palmitates / Q000378:metabolism; D010957:Plasmids / Q000235:genetics*; D011110:Polymorphism, Genetic; D011499:Protein Processing, Post-Translational; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D001426:Bacterial Proteins; D008074:Lipoproteins; D008565:Membrane Proteins; C102535:NlpH protein, Borrelia afzelii; D010168:Palmitates; D003224:Congo Red; D006427:Hemin