Journal article

Publication year: 1994

Pages: 253-261

Journal: European Journal of Biochemistry

Volume number: 225

Issue number: 1

ISSN: 0014-2956

Open access status: Bronze

DOI Link: https://doi.org/10.1111/j.1432-1033.1994.00253.x

Publisher: Wiley: No OnlineOpen

Abstract: 
The genes hdrA, hdrB and hdrC, encoding the three subunits of the iron-sulfur flavoprotein heterodisulfide reductase, have been cloned and sequenced. HdrA (72.19 kDa) was found to contain a region of amino acid sequence highly similar to the FAD-binding domain of pyridine-nucleotide-dependent disulfide oxidoreductases. Additionally, 110 amino acids C-terminal to the FAD-binding consensus, a short polypeptide stretch (VX(2)CATID) was detected which shows similarity to the region of thioredoxine reductase that contains the active-site cysteine residues (VX(2)CATCD). These findings suggest that HdrA harbors the site of heterodisulfide reduction and that the catalytic mechanism of the enzyme is similar to that of pyridine-nucleotide-dependent thioredoxin reductase. HdrA was additionally found to contain four copies of the sequence motif CX(2)CX(2)CX(3)C(P), indicating the presence of four [4Fe-4S] clusters. Two such sequence motifs were also present in HdrC (21.76 kDa), the N-terminal amino acid sequence of which showed sequence similarity to the gamma-subunit of the anaerobic glycerol-3-phosphate dehydrogenase of Escherichia coli. HdrC is therefore considered to be an electron carrier protein that contains two [4Fe-4S] clusters. HdrB (33.46 kDa) did not show sequence similarity to other known proteins, but appears to possess a C-terminal hydrophobic alpha-helix that might function as a membrane anchor. Although hdrB and hdrC are juxtaposed, these genes are not near hdrA.

Harvard Citation style: HEDDERICH, R., KOCH, J., LINDER, D. and THAUER, R. (1994) THE HETERODISULFIDE REDUCTASE FROM METHANOBACTERIUM-THERMOAUTOTROPHICUM CONTAINS SEQUENCE MOTIFS CHARACTERISTIC OF PYRIDINE-NUCLEOTIDE-DEPENDENT THIOREDOXIN REDUCTASES, European Journal of Biochemistry, 225(1), pp. 253-261. https://doi.org/10.1111/j.1432-1033.1994.00253.x

APA Citation style: HEDDERICH, R., KOCH, J., LINDER, D., & THAUER, R. (1994). THE HETERODISULFIDE REDUCTASE FROM METHANOBACTERIUM-THERMOAUTOTROPHICUM CONTAINS SEQUENCE MOTIFS CHARACTERISTIC OF PYRIDINE-NUCLEOTIDE-DEPENDENT THIOREDOXIN REDUCTASES. European Journal of Biochemistry. 225(1), 253-261. https://doi.org/10.1111/j.1432-1033.1994.00253.x