Molecular analysis of the channel-forming protein P13 and its paralogue family 48 from different Lyme disease Borrelia species.
The aetiological agent of Lyme disease, Borrelia burgdorferi cycles between its tick vector and mammalian hosts, implying that it can sense different environments and consequently change the expression of genes encoding several surface-associated proteins. The genome of the type strain B. burgdorferi B31 has revealed 175 different gene families. The p13 gene, situated on the chromosome, encodes a channel-forming protein that belongs to the gene family 48 consisting of eight additional paralogous genes. The heterogeneity of the P13 protein from different Lyme disease Borrelia strains was investigated. The predicted surface-exposed domains are the most heterogeneous regions and contain probable epitopes of P13. The membrane-spanning architecture of P13 was determined and a model for the location of this protein in the outer membrane is presented. The transcription of the paralogues of gene family 48 during in vitro culturing and in a mouse infection model was also analysed. The bba01 gene is the only p13 paralogue present in all three Lyme-disease-causing genospecies; it is stable during cultivation in vitro and the BBA01 protein was expressed in all Borrelia strains investigated. Conversely, paralogues bbi31, bbq06 and bbh41 were only detected in B. burgdorferi and the corresponding plasmids harbouring bbi31 and bbh41 were lost during in vitro passage. Finally, p13 and bbi31 are the only members of gene family 48 that are transcribed in mice, suggesting their importance during mammalian infection.
Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden.
Marija
M
Pinne
Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden.
Yngve
Y
Östberg
Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden.
Pär
P
Comstedt
Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden.
Sven
S
Bergström
D000595:Amino Acid Sequence; D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D001483:Base Sequence; D001898:Borrelia / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D004269:DNA, Bacterial / Q000235:genetics; D018604:Epitope Mapping; D005798:Genes, Bacterial; D006801:Humans; D007473:Ion Channels / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D008193:Lyme Disease / Q000382:microbiology; D051379:Mice; D008809:Mice, Inbred C3H; D008958:Models, Molecular; D008969:Molecular Sequence Data; D005810:Multigene Family; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D007473:Ion Channels