Structure of the flavocytochrome C sulfide dehydrogenase associated with the copper-binding protein CopC from the haloalkaliphilic sulfuroxidizing bacterium thioalkalivibrio paradoxus ArH 1

Eugeny M. Osipov, Anastasia V. Lilina, Stanislav I. Tsallagov, Tatyana N. Safonova, Dimitry Y. Sorokin, Tamara V. Tikhonova, Vladimir O. Popova

Research output: Contribution to journalArticleScientificpeer-review

4 Citations (Scopus)
82 Downloads (Pure)

Abstract

Flavocytochrome c sulfide dehydrogenase from Thioalkalivibrio paradoxus (TpFCC) is a heterodimeric protein consisting of flavin- and monohaem c-binding subunits. TpFCC was co-purified and co-crystallized with the dimeric copper-binding protein TpCopC. The structure of the TpFCC-(TpCopC)2 complex was determined by X-ray diffraction at 2.6 Å resolution. The flavin-binding subunit of TpFCC is structurally similar to those determined previously, and the structure of the haem-binding subunit is similar to that of the N-terminal domain of dihaem FCCs. According to classification based on amino-acid sequence, TpCopC belongs to a high-affinity CopC subfamily characterized by the presence of a conserved His1-Xxx-His3 motif at the N-terminus. Apparently, a unique α-helix which is present in each monomer of TpCopC at the interface withTpFCC plays a key role in complex formation. The structure of the copper-binding site in TpCopC is similar to those in other known CopC structures. His3 is not involved in binding to the copper ion and is 6-7 Å away from this ion. Therefore, the His1-Xxx-His3 motif cannot be considered to be a key factor in the high affinity of CopC for copper(II) ions. It is suggested that the TpFCC-(TpCopC)2 heterotetramer may be a component of a large periplasmic complex that is responsible for thiocyanate metabolism.

Original languageEnglish
Pages (from-to)632-642
JournalActa Crystallographica Section D: Structural Biology
Volume74
Issue number7
DOIs
Publication statusPublished - 1 Jul 2018

Keywords

  • CopC
  • Copper-binding protein
  • Flavocytochrome c sulfide dehydrogenase
  • Protein-protein complex
  • Thioalkalivibrio paradoxus
  • X-ray structure

Fingerprint Dive into the research topics of 'Structure of the flavocytochrome C sulfide dehydrogenase associated with the copper-binding protein CopC from the haloalkaliphilic sulfuroxidizing bacterium thioalkalivibrio paradoxus ArH 1'. Together they form a unique fingerprint.

Cite this