Probing plant GST activity using heterodimers and domain swapping

The activities of maize GSTs from the phi and tau classes were examined in recombinant bacteria expressing heterodimers or chimeric subunits. Heterodi mer formation was successful between GSTs within a class, but not between G STs from different classes. The activity and kinetics of heterodimers compa red with homodimers was additive; the subunit active sites appeared kinetic ally independent. N-terminal domains were swapped between GSTs to give chim eras; those formed between GSTs of different classes were inactive. Most in tra-class chimeras were active and allowed the influence of each of the two domains on various kinetic properties to be investigated. (C) 2001 Elsevie r Science Ireland Ltd. All rights reserved.