Elimination of channel-forming activity by insertional inactivation of the p13 gene in Borrelia burgdorferi
2002 (English)In: Journal of Bacteriology, ISSN 0021-9193, E-ISSN 1098-5530, Vol. 184, no 24, 6811-6819 p.Article in journal (Refereed) Published
P13 is a chromosomally encoded 13-kDa integral outer membrane protein of the Lyme disease agent, Borrelia burgdorferi. The aim of this study was to investigate the function of the P13 protein. Here, we inactivated the p13 gene by targeted mutagenesis and investigated the porin activities of outer membrane proteins by using lipid bilayer experiments. Channel-forming activity was lost in the p13 mutant compared to wild-type B. burgdorferi, indicating that P13 may function as a porin. We purified native P13 to homogeneity by fast performance liquid chromatography and demonstrated that pure P13 has channel-forming activity with a single-channel conductance in 1 M KCl of 3.5 nS, the same as the porin activity that was lost in the p13 mutant. Further characterization of the channel formed by P13 suggested that it is cation selective and voltage independent. In addition, no major physiological effects of the inactivated p13 gene could be detected under normal growth conditions. The inactivation of p13 is the first reported inactivation of a gene encoding an integral outer membrane protein in B. burgdorferi. Here, we describe both genetic and biophysical experiments indicating that P13 in B. burgdorferi is an outer membrane protein with porin activity.
Place, publisher, year, edition, pages
2002. Vol. 184, no 24, 6811-6819 p.
Cell and Molecular Biology
IdentifiersURN: urn:nbn:se:umu:diva-5029DOI: 10.1128/JB.184.24.6811-6819.2002PubMedID: 12446631OAI: oai:DiVA.org:umu-5029DiVA: diva2:144378