title: Histidine decarboxylase of Lactobacillus 30a. Sequences of the overlapping peptides, the complete alpha chain, and prohistidine decarboxylase.
abstract: The complete amino acid sequence of the alpha chain of histidine decarboxylase of Lactobacillus 30a has been established by isolation and analysis of the eight methionine-containing tryptic peptides of this chain. These peptides provide the overlaps required to order all nine peptides derived by complete cyanogen bromide cleavage of the alpha chain (Huynh, Q.K., Vaaler, G.L., Recsei, P.A., and Snell, E.E. (1984) J. Biol. Chem. 259, 2826-2832). Ordering of six of the latter peptides was confirmed by isolation and analysis of four peptides derived by incomplete cyanogen bromide cleavage. The alpha chain is composed of 226 residues and has a molecular weight of 24,892 calculated from the sequence. These results and the previously determined sequence of the beta chain (Vaaler, G.L., Recsei, P.A., Fox, J.L., and Snell, E.E. (1982) J. Biol. Chem. 257, 12770-12774) establish the complete amino acid sequence of the enzyme and of the pi chain of prohistidine decarboxylase. The latter is composed of 307 amino acids and has a calculated molecular weight of 33,731. Four segments of the pi chain sequence are repeated. The bond between Ser-81 and Ser-82 that is cleaved during proenzyme activation is in an uncharged portion of the sequence that is rich in serine and threonine residues and is predicted to be part of a beta sheet structure.
mesh_terms: D000595:Amino Acid Sequence; D002262:Carboxy-Lyases / Q000378:metabolism; D004789:Enzyme Activation; D004792:Enzyme Precursors; D006640:Histidine Decarboxylase / Q000378:metabolism; D007778:Lactobacillus / Q000201:enzymology*; D046911:Macromolecular Substances; D010446:Peptide Fragments / Q000032:analysis; D014357:Trypsin
chemical_list: D004792:Enzyme Precursors; D046911:Macromolecular Substances; D010446:Peptide Fragments; D014357:Trypsin; D002262:Carboxy-Lyases; D006640:Histidine Decarboxylase