Relative metastabilities of homologs of glutaredoxin and thioredoxin/thioredoxin reductase. Predominance diagrams were generated for subcellular isoforms of (a, c, e) glutaredoxin (GLRX) and of (b, d, f) thioredoxin (TRX) and thioredoxin reductase (TRXB) in S. cerevisiae. The letters in parentheses following the labels indicate the subcellular compartment to which the protein is localized (C – cytoplasm; M – mitochondrion; N – nucleus). Calculations were performed for ionized proteins at 25°C and 1 bar and for reference activities of basis species noted in the Methods. Reduction stability limits of H2O are shown by dashed lines; the dotted lines in (c) and (d) correspond to the plot limits of (a) and (b).