Studies of an active site mutant of the selenoprotein thioredoxin reductase: the Ser-Cys-Cys-Ser motif of the insect orthologue is not sufficient to replace the Cys-Sec dyad in the mammalian enzyme.

Abstract excerpt

We have mutated the redox active C-terminal motif, Gly-Cys-Sec-Gly, of the mammalian selenoprotein thioredoxin reductase (TrxR) to mimic the C-terminal Ser-Cys-Cys-Ser motif of the non-selenoprotein orthologue of Drosophila melanogaster (DmTrxR). The activity of DmTrxR is almost equal to that of mammalian TrxR, which is surprising, because Cys mutants of selenoproteins are normally 1-2 orders of magnitude less...

Topics

• Amino Acid Motifs
• Amino Acid Sequence
• Animals
• Base Sequence
• Binding Sites
• Cysteine
• DNA Primers
• Drosophila melanogaster
• Electrophoresis, Polyacrylamide Gel
• Molecular Sequence Data
• Mutation
• Sequence Homology, Amino Acid