The -Cys-X1-X2-Cys- motif of reduced glutaredoxins adopts a consensus structure that explains the low pK(a) of its catalytic cysteine.

The -Cys-X1-X2-Cys- active site motif is central to the function of enzymes of the thioredoxin superfamily, including glutaredoxins. Their chemistry depends on the lowered pK(a) of the N-terminal thiolate cysteine of the -Cys-X1-X2-Cys- sequence; therefore its structure, dynamics, and electrostatics matter. Much information about the glutaredoxin structures… CONTINUE READING