Water, Air, & Soil Pollution

, Volume 223, Issue 7, pp 4443–4457 | Cite as

Bioinformatic Analyses of Bacterial Mercury Ion (Hg2+) Transporters

  • Timothy Mok
  • Jonathan S. Chen
  • Maksim A. Shlykov
  • Milton H. SaierJr


Currently, there are five known types of mercury transporters in bacteria: MerC, MerE, MerF, MerH, and MerT. Their general function is to mediate mercuric ion uptake into the cell in preparation for reduction to Hg°. They are present in several bacterial phyla and comprise five distinct families. We have utilized standard statistical bioinformatic tools and the superfamily principle to show that they are related by common descent. After using programs such as Global Alignment Program and SSearch to establish homology, we aligned and analyzed their amino acid sequences to find a single well conserved motif. Although these proteins exhibit 2, 3, or 4 transmembrane helical segments (TMSs), TMSs 1 and 2 are common to all superfamily members. An ancestral sequence was determined, and reliable phylogenetic trees were constructed. The results support the conclusion of homology, establishing that these proteins belong to a single superfamily. This important discovery allows extrapolation of information about structure, function, and mechanism from one protein to all superfamily members to degrees inversely proportional to their phylogenetic distances.


Transport Hg2+ channel Protein superfamily Bioremediation Bacteria 



This work was supported by NIH grant GM 077402.

Supplementary material

11270_2012_1208_MOESM1_ESM.ppt (1.2 mb)
ESM 1 PPT 1,178 kb


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Copyright information

© Springer Science+Business Media B.V. 2012

Authors and Affiliations

  • Timothy Mok
    • 1
  • Jonathan S. Chen
    • 1
  • Maksim A. Shlykov
    • 1
  • Milton H. SaierJr
    • 1
  1. 1.Division of Biological SciencesUniversity of California at San DiegoLa JollaUSA

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