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Publication Abstract from PubMed

Pathogenic Leptospira species are the etiological agents of the widespread zoonotic disease leptospirosis. Most organisms, including Leptospira, require divalent cations for proper growth, but because of their high reactivity these metals are toxic at high concentration. Therefore, bacteria have acquired strategies to maintain metal homeostasis, such as metal import and efflux. By screening Leptospira biflexa transposon mutants for their ability to use Mn2+, we have identified a gene encoding a putative orphan ATP-binding cassette (ABC) ATPase of unknown function. Inactivation of this gene in both L. biflexa and L. interrogans strains led to mutants unable to grow in medium in which iron was substituted by Mn2+, suggesting an involvement of this ABC ATPase in divalent cation uptake. Mutation in this ATPase-coding gene increased susceptibility to Mn2+ toxicity. Recombinant ABC ATPase of the pathogen L. interrogans exhibited Mg2+-dependent ATPase activity involving a P-loop motif. The structure of this ATPase was solved from a crystal containing two monomers in the asymmetric unit. Each monomer adopted a canonical two-subdomain organization of the ABC-ATPase fold with an alpha/beta subdomain containing the Walker motifs and an alpha subdomain containing the ABC signature motif (LSGGE). The two monomers were arranged in a head-to-tail orientation forming a V-shaped particle with all the conserved ABC motifs at the dimer interface, similar to functional ABC ATPases. These results provide the first structural and functional characterization of a leptospiral ABC ATPase.

Structural and functional characterization of an orphan ATP-binding cassette ATPase involved in manganese utilization and tolerance in Leptospira spp.,Benaroudj N, Saul F, Bellalou J, Miras I, Weber P, Bondet V, Murray GL, Adler B, Ristow P, Louvel H, Haouz A, Picardeau M J Bacteriol. 2013 Oct 11. PMID:24123817^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.