Plasmids pMOL28 and pMOL30 of Cupriavidus metallidurans are specialised in the maximal viable response to heavy metals

Sébastien Monchy, Rafi Benotmane, Paul Janssen, Tatiana Vallaeys, Safiyh Taghavi, Daniel van der Lelie, Max Mergeay, Rob Van Houdt

    Research outputpeer-review


    We fully reannotated two large plasmids, pMOL28 (164 ORFs; 171 459 bp) and pMOL30 (247 ORFs; 233 720 bp), in the genome of Cupriavidus metallidurans CH34. Genes involved in the resistance to the heavy metals Co(II), Cr(VI), Hg(II), and Ni(II) are concentrated within a region of 34kb on pMOL28; those involved in the resistance to Ag(I), Cd(II), Co(II), Cu(II), Hg(II), Pb(II), and Zn(II) occur within a 132kb region on pMOL30. We identified putative genomic islands containing metal-resistance operons flanked by mobile genetic elements, one on pMOL28 and two on pMOL30. Transcriptomic analysis using quantitative PCR and microarrays revealed the metal-mediated up-regulation of 83 genes on pMOL28 and of 143 genes on pMOL30 that coded for all known heavy-metal resistance proteins, membrane proteins, truncated transposases, conjugative transfer-proteins, and many unknown proteins, and for some new ones (czcJ, mmrQ, and pbrU). Five genes on each plasmid were down-regulated; for one of them, chrI localised on pMOL28, this occurs in the presence of five cations. We observed multiple cross-responses ,suggesting that the cellular defences of C. metallidurans against heavy metal stress involves various regulons, and probably has multiple stages including a more general response, and a more metal-specific one
    Original languageEnglish
    Pages (from-to)7417-7425
    JournalJournal of Bacteriology
    Issue number20
    StatePublished - 1 Oct 2007

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