Your browser version may not work well with NCBI's Web applications. More information here...
1: FEBS Lett. 1994 May 23;345(1):76-80.Click here to read Links

Characterization of the paramagnetic iron-containing redox centres of Thiosphaera pantotropha periplasmic nitrate reductase.

Breton J, Berks BC, Reilly A, Thomson AJ, Ferguson SJ, Richardson DJ.

Centre for Metalloprotein Spectroscopy and Biology, School of Biological Sciences, University of East Anglia, Norwich, UK.

Electron paramagnetic resonance spectroscopy signals attributable to low-spin haem c in the oxidised protein and [4Fe-4S]1+ in the dithionite-reduced protein were identified, at low temperature, in Thiosphaera pantotropha periplasmic nitrate reductase. Spin integration of these signals as well as elemental analysis suggest a stoichiometry of 1.3-1.6 c-haem and 1 [4Fe-4S] cluster per enzyme molecule. The Em (at pH 7.4) of the [4Fe-4S]2+,1+ couple, -160 mV, means that it is unlikely to be physiologically reducible. Peptide sequences from the 90 kDa subunit indicate that the enzyme is a member of the family of molybdopterin guanine dinucleotide-binding polypeptides, the majority of which possess a putative [4Fe-4S] cluster binding sequence and thus may also bind a (low potential) iron-sulphur cluster.

PMID: 8194605 [PubMed - indexed for MEDLINE]