The amino acid sequence of plastocyanin from Lactuca sativa (lettuce)

The amino acid sequence of plastocyanin from lettuce (Lactuca sativa L.) was determined by using a Beckman 890C automatic sequencer and by dansyl-phenylisothiocyanate analysis of peptides obtained by enzymic digestion of purified CNBr fragments. The protein consists of a single polypeptide chain of 99 residues, and shows close homology with other higher plant plastocyanins. The data are discussed in relation to the possible residues involved in the binding of copper in plastocyanin.