Journal of Molecular Evolution

, Volume 57, Issue 4, pp 363–376

Horizontal Gene Transfer of “Prototype” Nramp in Bacteria

  • Etienne Richer
  • Pascal Courville
  • Isabelle Bergevin
  • Mathieu F. M. Cellier
Article

DOI: 10.1007/s00239-003-2472-z

Cite this article as:
Richer, E., Courville, P., Bergevin, I. et al. J Mol Evol (2003) 57: 363. doi:10.1007/s00239-003-2472-z

Abstract

Eukaryotic Nramp genes encode divalent metal ion permeases important for nutrition and resistance to microbial infection. Bacterial homologs encode proton-dependent transporters of manganese (MntH), and other divalent metal ions. Bacterial MntH were classified in three homology groups (A, B, C) and MntH C further subdivided in Cα, Cβ, Cγ. The proteins from C. tepidum (MntH B) and E. faecalis (MntH Cβ1, 2), divergent in sequence and hydropathy profile, conferred increased metal sensitivity when expressed in E. coli, suggesting conservation of divalent metal transport function in MntH B and C. Several genomic evidence suggest horizontal gene transfer (HGT) of mntH C genes: (i) The enterobacteria WigglesworthiamntH Cβ gene is linked to an Asnt-RNA, and its sequence most conserved with Gram positive bacteria homologs; (ii) all the Cβ genes identified in oral streptococcaceae are associated with different potentially mobile DNA elements; (iii) Lactococcuslactis and Burkholderiamallei genomes contain an mntH gene prematurely terminated and a novel full-length mntH C gene; (iv) remarkable sequence relatedness between the unicellular alga C. reinhardtii “prototype” Nramp and some MntH Cα (e.g., Nostoc spp., Listeria spp.) suggests HGT between Eukarya and Bacteria. Other “prototype” Nramp genes (intronless, encoding proteins strongly conserved with MntH A and B proteins) identified in invertebrates represent a possible source for transfer of Nramp genes toward opportunistic bacteria. This study demonstrates complex evolution of MntH in Bacteria. It is proposed that “prototype” Nramp are ancestors of bacterial MntH C proteins, which could facilitate bacterial infection.

Keywords

Phylogenetic analyses Bacterial–eukaryotic protein similarity Metal permeases Bacterial infection 

Copyright information

© Springer-Verlag New York Inc. 2003

Authors and Affiliations

  • Etienne Richer
    • 1
  • Pascal Courville
    • 1
  • Isabelle Bergevin
    • 1
  • Mathieu F. M. Cellier
    • 1
  1. 1.INRS-Institut Armand-Frappier, 531, Bd des prairies, Laval, PQCanada H7V 1B7

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