Role of the cysteine residues in Arabidopsis thaliana cyclophilin CYP20-3 in peptidyl-prolyl cis-trans isomerase and redox-related functions.

ABSTRACT: Cyps (cyclophilins) are ubiquitous proteins of the immunophilin superfamily with proposed functions in protein folding, protein degradation, stress response and signal transduction. Conserved cysteine residues further suggest a role in redox regulation. In order to get insight into the conformational change mechanism and functional properties of the chloroplast-located CYP20-3, site-directed mutagenized cysteine-->serine variants were generated and analysed for enzymatic and conformational properties under reducing and oxidizing conditions. Compared with the wild-type form, elimination of three out of the four cysteine residues decreased the catalytic efficiency of PPI (peptidyl-prolyl cis-trans isomerase) activity of the reduced CYP20-3, indicating a regulatory role of dithiol-disulfide t

SUBMITTER: Laxa M 

PROVIDER: S-EPMC1698676 | biostudies-literature | 2007 Jan

REPOSITORIES: biostudies-literature