Covalent structure of protein C. A second major low molecular weight protein degraded during germination of Bacillus megaterium spores

Abstract

The complete covalent structure of protein C, a protein degraded during germination of Bacillus megaterium spores, has been determined. The intact protein was cleaved with a highly specific spore protease into two peptides, residues 1 to 30 and 31 to 71. The intact protein was also cleaved by cyanogen bromide into two peptides, residues 1 to 27 and 28 to 71. Cleavage of the larger cyanogen bromide peptide with trypsin allowed isolation of the COOH-terminal peptide, residues 59 to 71. Automated sequenator analysis of the intact protein and peptide fragments, together with previously published partial sequence data on this protein and carboxypeptidase A digestion of the intact protein provided data from which the following unique sequence was deduced: (formula: see text). The primary sequence of the C protein shows an extremely high degree of homology with that of the A protein--another protein degraded during germination of B. megaterium spores.