Structural studies on yeast 3-phosphoglycerate kinase. Linear arrangement of the CNBr fragments, partial amino acid sequence of the inner part of the polypeptide chain, and analyses of the N-terminal domain of the protein.

The purpose of this work was to contribute to the study of the covalent structure of yeast 3-phosphoglycerate kinase. First, we undertook the complete alignment of the four fragments produced by cyanogen-bromide cleavage and which constitute the intact protein; we then established the total amino acid sequence of a 30-residue peptide and the N-terminal sequence of a 65-residue peptide. Second, we analyzed the acetylated state of the protein. The analyses of the acid fraction "P" obtained after digestion of 3-phosphoglycerate kinase by pronase enabled us to determine the N-terminal sequence of this enzyme as N-acetylserylglycine. Third, we isolated, purified and analyzed seven tryptic peptides from a fragment containing 102 amino acids coming from the N-terminal end of the protein. The peptides occupying the N- and C-terminal ends of this fragment were also identified.