Reductive power of the archaea right-handed coiled coil nanotube (RHCC-NT) and incorporation of mercury clusters inside protein cages?
Matthew Mc Dougall, Kevin McEleney, Olga Francisco, Benchmen Trieu, Efehi Kelly Ogbomo, Gregg Tomy, Jörg Stetefeld
Department of Chemistry, University of Manitoba, 144 Dysart Rd, Winnipeg, Manitoba, Canada.
Coiled coils are well described as powerful oligomerization motifs and exhibit a large diversity of functions, including gene regulation, cell division, membrane fusion and drug extrusion. The archaea S-layer originated right-handed coiled coil –RHCC-NT- is characterized by extreme stability and is free of cysteine and histidine moieties. In the current study, we have followed a multidisciplinary approach to investigate the capacity of RHCC-NT to bind a variety of ionic complex metal ions. At the outside of the RHCC-NT, one mercury ion forms an electrostatic interaction with the S-methyl moiety of the single methionine residue present in each coil. We demonstrate that RHCC-NT is reducing and incorporating metallic mercury in the large-sized interior cavities which are lined up along the tetrameric channel.
Keywords: Archaea, S-layer, Right-handed coiled coil, Reduction of metals, Cluster uptake via protein cage, Synchrotron-XRD, XPS.