title: Advanced electron paramagnetic resonance on the catalytic iron-sulfur cluster bound to the CCG domain of heterodisulfide reductase and succinate: quinone reductase.
abstract: Heterodisulfide reductase (Hdr) is a key enzyme in the energy metabolism of methanogenic archaea. The enzyme catalyzes the reversible reduction of the heterodisulfide (CoM-S-S-CoB) to the thiol coenzymes M (CoM-SH) and B (CoB-SH). Cleavage of CoM-S-S-CoB at an unusual FeS cluster reveals unique substrate chemistry. The cluster is fixed by cysteines of two cysteine-rich CCG domain sequence motifs (CX31-39CCX35-36CXXC) of subunit HdrB of the Methanothermobacter marburgensis HdrABC complex. We report on Q-band (34 GHz) (57)Fe electron-nuclear double resonance (ENDOR) spectroscopic measurements on the oxidized form of the cluster found in HdrABC and in two other CCG-domain-containing proteins, recombinant HdrB of Hdr from M. marburgensis and recombinant SdhE of succinate: quinone reductase from Sulfolobus solfataricus P2. The spectra at 34 GHz show clearly improved resolution arising from the absence of proton resonances and polarization effects. Systematic spectral simulations of 34 GHz data combined with previous 9 GHz data allowed the unambiguous assignment of four (57)Fe hyperfine couplings to the cluster in all three proteins. (13)C Mims ENDOR spectra of labelled CoM-SH were consistent with the attachment of the substrate to the cluster in HdrABC, whereas in the other two proteins no substrate is present. (57)Fe resonances in all three systems revealed unusually large (57)Fe ENDOR hyperfine splitting as compared to known systems. The results infer that the cluster's unique magnetic properties arise from the CCG binding motif.
authors.affiliation: Max Planck Institute for Biophysical Chemistry, Göttingen, Germany, alistair.fielding@manchester.ac.uk.
authors.forename: Alistair J
authors.initials: AJ
authors.lastname: Fielding
authors.forename: Kristian
authors.initials: K
authors.lastname: Parey
authors.forename: Ulrich
authors.initials: U
authors.lastname: Ermler
authors.forename: Silvan
authors.initials: S
authors.lastname: Scheller
authors.forename: Bernhard
authors.initials: B
authors.lastname: Jaun
authors.forename: Marina
authors.initials: M
authors.lastname: Bennati
mesh_terms: D000595:Amino Acid Sequence; D004578:Electron Spin Resonance Spectroscopy; D007506:Iron-Sulfur Proteins / Q000737:chemistry / Q000378:metabolism*; D017013:Methanobacteriaceae / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D008969:Molecular Sequence Data; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000737:chemistry / Q000378:metabolism*; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D019802:Succinic Acid / Q000378:metabolism*; D048229:Sulfolobus solfataricus / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism
chemical_list: D007506:Iron-Sulfur Proteins; D019802:Succinic Acid; D010088:Oxidoreductases; C087171:heterodisulfide reductase; D016660:NAD(P)H Dehydrogenase (Quinone)
references.citation: Biochemistry. 1990 Nov 20;29(46):10533-40
references.pmid: 2271662
references.citation: FEBS Lett. 2002 Feb 13;512(1-3):263-8
references.pmid: 11852093
references.citation: Biochim Biophys Acta. 2002 Jan 17;1553(1-2):1-6
references.pmid: 11803013
references.citation: Biochemistry. 1998 Mar 31;37(13):4612-20
references.pmid: 9521781
references.citation: Biochemistry. 2001 Oct 30;40(43):13068-78
references.pmid: 11669645
references.citation: Biochemistry. 1989 May 30;28(11):4861-71
references.pmid: 2765515
references.citation: J Biol Chem. 1985 Jun 10;260(11):6871-81
references.pmid: 2987236
references.citation: Eur J Biochem. 2001 May;268(9):2566-77
references.pmid: 11322875
references.citation: Biochemistry. 2007 Nov 6;46(44):12875-85
references.pmid: 17929940
references.citation: Biol Chem. 2005 Oct;386(10):961-70
references.pmid: 16218868
references.citation: Proc Natl Acad Sci U S A. 1983 Aug;80(15):4674-8
references.pmid: 6308639
references.citation: J Am Chem Soc. 2010 Feb 17;132(6):2037-49
references.pmid: 20099820
references.citation: Biochemistry. 1990 Nov 20;29(46):10526-32
references.pmid: 2176871
references.citation: Chem Rev. 1996 Nov 7;96(7):2335-2374
references.pmid: 11848830
references.citation: J Magn Reson B. 1995 Jul;108(1):99-102
references.pmid: 7627437
references.citation: Proc Natl Acad Sci U S A. 2013 Jan 8;110(2):483-8
references.pmid: 23267108
references.citation: J Magn Reson. 2011 Jan;208(1):76-86
references.pmid: 21075026
references.citation: Microbiology (Reading). 1998 Sep;144 ( Pt 9):2377-2406
references.pmid: 9782487
references.citation: J Am Chem Soc. 2011 Jun 8;133(22):8400-3
references.pmid: 21574560
references.citation: Science. 2000 Jan 28;287(5453):655-8
references.pmid: 10649999
references.citation: Biochemistry. 2005 Oct 4;44(39):13151-62
references.pmid: 16185083
references.citation: Nat Rev Microbiol. 2008 Aug;6(8):579-91
references.pmid: 18587410
references.citation: FEBS Lett. 2003 Mar 13;538(1-3):81-4
references.pmid: 12633857
references.citation: J Am Chem Soc. 2002 Mar 27;124(12):3143-51
references.pmid: 11902903
references.citation: Eur J Biochem. 1994 Oct 1;225(1):253-61
references.pmid: 7925445
references.citation: Biochemistry. 1991 Dec 10;30(49):11579-84
references.pmid: 1660722
references.citation: Proc Natl Acad Sci U S A. 2011 Feb 15;108(7):2981-6
references.pmid: 21262829
references.citation: Biochim Biophys Acta. 1975 Jan 31;376(1):63-71
references.pmid: 164903
references.citation: J Am Chem Soc. 2004 Jul 14;126(27):8378-9
references.pmid: 15237985
references.citation: J Biol Inorg Chem. 2009 Mar;14(3):457-70
references.pmid: 19085017
references.citation: J Am Chem Soc. 2003 Feb 5;125(5):1146-7
references.pmid: 12553798
references.citation: Eur J Biochem. 2002 Apr;269(8):2117-23
references.pmid: 11985589