Open AccessCloning and Functional Analysis of the pbr Lead Resistance Determinant of Ralstonia metallidurans CH34
Author(s) -
B. Borremans,
Jon L. Hobman,
Ann Provoost,
Nigel L. Brown,
Daniël van der Lelie
Publication year - 2001
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.183.19.5651-5658.2001
Subject(s) - operon , biology , efflux , gene , ralstonia , integral membrane protein , genetics , locus (genetics) , microbiology and biotechnology , biochemistry , membrane protein , escherichia coli , membrane
The lead resistance operon, pbr, of Ralstonia metallidurans (formerly Alcaligenes eutrophus) strain CH34 is unique, as it combines functions involved in uptake, efflux, and accumulation of Pb(II). The pbr lead resistance locus contains the following structural resistance genes: (i) pbrT, which encodes a Pb(II) uptake protein; (ii) pbrA, which encodes a P-type Pb(II) efflux ATPase; (iii) pbrB, which encodes a predicted integral membrane protein of unknown function; and (iv) pbrC, which encodes a predicted prolipoprotein signal peptidase. Downstream of pbrC, the pbrD gene, encoding a Pb(II)-binding protein, was identified in a region of DNA, which was essential for functional lead sequestration. Pb(II)-dependent inducible transcription of pbrABCD from the PpbrA promoter is regulated by PbrR, which belongs to the MerR family of metal ion-sensing regulatory proteins. This is the first report of a mechanism for specific lead resistance in any bacterial genus.