Structural and functional studies of XvPrx2, a type II peroxiredoxin protein from the resurrection plant xerophyta viscosa
XvPrx2 is a 1-Cys-containing member of the Prx5 subfamily of peroxiredoxins isolated from the resurrection plant Xerophyta viscosa. It is reported to be up-regulated during periods of desiccation and to protect nucleic acids and cellular proteins from oxidative damage through scavenging of reactive oxygen species, suggesting that it may play a role the desiccation tolerance of X. viscosa (Govender, 2006). Members of the Prx5 subfamily have previously been reported to occur as non-covalent homodimers associating across an A-type interface. PrxD from Populus tremula, a close homologue of XvPrx2, forms disulphide bonds with glutathione (glutathionylation) resulting in the unfolding of the Cp-loop and α2-helix and disruption of the homodimer, on the basis of which glutathionylation has been proposed as a physiological mechanism for regeneration of all members of the Prx5 subfamily (Noguera-Mazon, et al., 2006b).