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Literature summary for extracted from

  • Shen, Y.; Chen, J.; Shen, W.; Chen, C.; Lin, Z.; Li, C.
    Molecular characterization of a novel sulfide quinone oxidoreductase from the razor clam Sinonovacula constricta and its expression response to sulfide stress (2020), Comp. Biochem. Physiol. B, 239, 110367 .
    View publication on PubMed


Cloned (Comment) Organism
gene sqr, DNA and amino acid sequence determination and analysis, sequence comparisons, quantitative real-time RT-PCR expression analysis, recombinant expression of N- and C-terminally His-tagged enzyme in Escherichia coli strain BL21 in inclusion bodies Sinonovacula constricta


Localization Comment Organism GeneOntology No. Textmining
mitochondrion ScSQR is located only in the mitochondria, no signal peptide is found Sinonovacula constricta 5739

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
hydrogen sulfide + glutathione + ubiquinone Sinonovacula constricta
S-sulfanylglutathione + ubiquinol


Organism UniProt Comment Textmining
Sinonovacula constricta A0A6B9CM12

Posttranslational Modification

Posttranslational Modification Comment Organism
glycoprotein three putative glycosylation sites (NNTV, NISY, NTSL) are predicted Sinonovacula constricta

Purification (Commentary)

Purification (Comment) Organism
recombinant His-tagged enzyme from Escherichia coli strain BL21 by nickel affinity chromatography from inclusion bodies. Native enzyme partially from gills by purification of mitochondria Sinonovacula constricta

Source Tissue

Source Tissue Comment Organism Textmining
Sinonovacula constricta
Sinonovacula constricta

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
hydrogen sulfide + glutathione + ubiquinone
Sinonovacula constricta S-sulfanylglutathione + ubiquinol


Subunits Comment Organism
? x * 56000, recombinant His-tagged enzyme SDS-PAGE Sinonovacula constricta


Synonyms Comment Organism
Sinonovacula constricta
Sinonovacula constricta
sulfide:quinone oxidoreductase
Sinonovacula constricta


Cofactor Comment Organism Structure
FAD the deduced ScSQR protein contains conserved FAD-binding domains, comprising residues 32-59, 121-134, and 306-331 Sinonovacula constricta
Sinonovacula constricta


Organism Comment Expression
Sinonovacula constricta enzyme expression is induced by 0.15 mM sulfide. In the gill, the expression level of ScSQR increases significantly and shows a time-dependent pattern. In addition, under sulfide stress, the expression level of the gill is higher than that of liver, overview up

General Information

General Information Comment Organism
additional information the deduced ScSQR protein contains conserved FAD-binding domains, two cysteine residues (C190 and C371), two histidines (H68 and H282), and one glutamic acid (E147), which are the essential elements for the catalytic mechanism of SQR Sinonovacula constricta
physiological function due to the little exchange of seawater and to anoxic conditions, Sinonovacula constricta is exposed to considerable amounts of sulfide during low tide, but exhibits strong sulfide tolerance. Mitochondrial sulfide oxidation is a particular defense strategy against sulfide toxicity of sulfide-tolerant organisms, for which sulfide:quinone oxidoreductase (SQR) is the first key enzyme. In order to investigate the mechanism of sulfide tolerance including ScSQR. Th enzyme has an important role in protecting cells from sulfide stress by participating in mitochondrial sulfide detoxification, it catalyzes electron transfer from sulfide to ubiquinone through the FAD cofactor Sinonovacula constricta