| | QSOX contains a pseudo-dimer of functional and degenerate sulfhydryl oxidase domainsEdited by Kaspar Locher Received 31 January 2010; received in revised form 2 March 2010; accepted 2 March 2010. published online 10 March 2010. Abstract 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. a Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel b Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA Corresponding author. Fax: +972 8 934 4136.
PII: S0014-5793(10)00194-8 doi:10.1016/j.febslet.2010.03.001 © 2010 Federation of European Biochemical Societies | |
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