3llk is a 3 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
QSOX1_HUMAN Catalyzes the oxidation of sulfhydryl groups in peptide and protein thiols to disulfides with the reduction of oxygen to hydrogen peroxide. May contribute to disulfide bond formation in a variety of secreted proteins. In fibroblasts, it may have tumor-suppressing capabilities being involved in growth regulation.[1][2][3][4][5][6]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Quiescin sulfhydryl oxidase (QSOX) catalyzes formation of disulfide bonds between cysteine residues in substrate proteins. Human QSOX1 is a multi-domain, monomeric enzyme containing a module related to the single-domain sulfhydryl oxidases of the Erv family. A partial QSOX1 crystal structure reveals a single-chain pseudo-dimer mimicking the quaternary structure of Erv enzymes. However, one pseudo-dimer "subunit" has lost its cofactor and catalytic activity. In QSOX evolution, a further concatenation to a member of the protein disulfide isomerase family resulted in an enzyme capable of both disulfide formation and efficient transfer to substrate proteins.
QSOX contains a pseudo-dimer of functional and degenerate sulfhydryl oxidase domains.,Alon A, Heckler EJ, Thorpe C, Fass D FEBS Lett. 2010 Apr 16;584(8):1521-5. Epub 2010 Mar 6. PMID:20211621[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑Radom J, Colin D, Thiebault F, Dognin-Bergeret M, Mairet-Coello G, Esnard-Feve A, Fellmann D, Jouvenot M. Identification and expression of a new splicing variant of FAD-sulfhydryl oxidase in adult rat brain. Biochim Biophys Acta. 2006 May;1759(5):225-33. Epub 2006 May 9. PMID:16806532 doi:https://dx.doi.org/10.1016/j.bbaexp.2006.04.008
↑Hoober KL, Glynn NM, Burnside J, Coppock DL, Thorpe C. Homology between egg white sulfhydryl oxidase and quiescin Q6 defines a new class of flavin-linked sulfhydryl oxidases. J Biol Chem. 1999 Nov 5;274(45):31759-62. PMID:10542195
↑Coppock D, Kopman C, Gudas J, Cina-Poppe DA. Regulation of the quiescence-induced genes: quiescin Q6, decorin, and ribosomal protein S29. Biochem Biophys Res Commun. 2000 Mar 16;269(2):604-10. PMID:10708601 doi:https://dx.doi.org/10.1006/bbrc.2000.2324
↑Thorpe C, Hoober KL, Raje S, Glynn NM, Burnside J, Turi GK, Coppock DL. Sulfhydryl oxidases: emerging catalysts of protein disulfide bond formation in eukaryotes. Arch Biochem Biophys. 2002 Sep 1;405(1):1-12. PMID:12176051
↑Chakravarthi S, Jessop CE, Willer M, Stirling CJ, Bulleid NJ. Intracellular catalysis of disulfide bond formation by the human sulfhydryl oxidase, QSOX1. Biochem J. 2007 Jun 15;404(3):403-11. PMID:17331072 doi:https://dx.doi.org/10.1042/BJ20061510
↑Heckler EJ, Alon A, Fass D, Thorpe C. Human quiescin-sulfhydryl oxidase, QSOX1: probing internal redox steps by mutagenesis. Biochemistry. 2008 Apr 29;47(17):4955-63. doi: 10.1021/bi702522q. Epub 2008 Apr, 5. PMID:18393449 doi:https://dx.doi.org/10.1021/bi702522q
↑Alon A, Heckler EJ, Thorpe C, Fass D. QSOX contains a pseudo-dimer of functional and degenerate sulfhydryl oxidase domains. FEBS Lett. 2010 Apr 16;584(8):1521-5. Epub 2010 Mar 6. PMID:20211621 doi:10.1016/j.febslet.2010.03.001
