Two forms of pyruvate kinase in Escherichia coli. a comparison of chemical and molecular properties
Valentini, G.; Iadarola, P.; Somani, B.L.; Malcovati, M.
Biochimica et Biophysica Acta 570(2): 248-258
The two forms of pyruvate kinase (ATP:pyruvate 2-O-phosphotransferase, EC 188.8.131.52) present in Escherichia coli have been purified from the same cultures and crystallized. A modified procedure for the purification of type I pyruvate kinase is described. Molecular weight, subunit structure, amino acid composition, NH2-terminal amino acid, maps of tryptic peptides and conditions for crystallization have been determined for the two forms. A comparison of these data shows that the two forms are different proteins, each being a tetramer of identical subunits.