%0 Journal Article
%A Hollenstein, Kaspar
%A Comellas-Bigler, Mireia
%A Bevers, Loes E.
%A Feiters, Martin C.
%A Meyer-Klaucke, Wolfram
%A Hagedoorn, Peter-Leon
%A Locher, Kaspar P.
%T Distorted octahedral coordination of tungstate in a subfamily of specific binding proteins
%J Journal of biological inorganic chemistry
%V 14
%N 5
%@ 1432-1327
%C Berlin
%I Springer
%M PUBDB-2016-02463
%P 663 - 672
%D 2009
%Z (c) SBIC
%X Bacteria and archaea import molybdenum andtungsten from the environment in the form of theoxyanions molybdate (MoO42-) and tungstate (WO42-).These substrates are captured by an external, high-affinitybinding protein, and delivered to ATP binding cassettetransporters, which move them across the cell membrane.We have recently reported a crystal structure of themolybdate/tungstate binding protein ModA/WtpA fromArchaeoglobus fulgidus, which revealed an octahedrallycoordinated central metal atom. By contrast, the previouslydetermined structures of three bacterial homologs showedtetracoordinate molybdenum and tungsten atoms in theirbinding pockets. Until then, coordination numbers abovefour had only been found for molybdenum/tungsten inmetalloenzymes where these metal atoms are part of thecatalytic cofactors and coordinated by mostly non-oxygenligands. We now report a high-resolution structure ofA. fulgidus ModA/WtpA, as well as crystal structures offour additional homologs, all bound to tungstate. Thesecrystal structures match X-ray absorption spectroscopymeasurements from soluble, tungstate-bound protein, andreveal the details of the distorted octahedral coordination.Our results demonstrate that the distorted octahedralgeometry is not an exclusive feature of the A. fulgidusprotein, and suggest distinct binding modes of the bindingproteins from archaea and bacteria.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:19234723
%U <Go to ISI:>//WOS:000266924400003
%R 10.1007/s00775-009-0479-7
%U https://bib-pubdb1.desy.de/record/300896