“…The blue single-Cu proteins whose crystal structures have been published are poplar plastocyanin (Guss & Freeman, 1983;Guss et al, 1992), Enteromorpha prolifera plastocyanin (Collyer et al, 1990), Chlamydomonas reinhardtii plastocyanin (Redinbo et al, 1993), Alcaligenes denitrificans azurin (Baler, 1988), Pseudomonas aeruginosa azurin (Adman & Jensen, 1981;Nar et al, 1991), Alcaligenes faecalis S-6 pseudoazurin (Petratos et al, 1988;Adman et al, 1989), Methylobacterium extorquens AM1 pseudoazurin (Inoue et al, 1994), Paracoccus denitrificans amicyanin (Durley et al, 1993), Thiobacillus versutus amicyanin (Romero et al, 1994), and the cucumber basic blue protein (Guss et al, 1988). The cited references deal with the structures of the proteins in the Cu II state.…”