title: Cloning and nucleotide sequence of wild type and a mutant histidine decarboxylase from Lactobacillus 30a.
abstract: Prohistidine decarboxylase from Lactobacillus 30a is a protein that autoactivates to histidine decarboxylase by cleaving its peptide chain between serines 81 and 82 and converting Ser-82 to a pyruvoyl moiety. The pyruvoyl group serves as the prosthetic group for the decarboxylation reaction. We have cloned and determined the nucleotide sequence of the gene for this enzyme from a wild type strain and from a mutant with altered autoactivation properties. The nucleotide sequence modifies the previously determined amino acid sequence of the protein. A tripeptide missed in the chemical sequence is inserted, and three other amino acids show conservative changes. The activation mutant shows a single change of Gly-58 to an Asp. Sequence analysis up- and downstream from the gene suggests that histidine decarboxylase is part of a polycistronic message, and that the transcriptional promotor region is strongly homologous to those of other Gram-positive organisms.
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002262:Carboxy-Lyases / Q000235:genetics*; D003001:Cloning, Molecular; D003062:Codon; D004262:DNA Restriction Enzymes; D005796:Genes; D005798:Genes, Bacterial; D006640:Histidine Decarboxylase / Q000235:genetics*; D007778:Lactobacillus / Q000201:enzymology / Q000235:genetics*; D009154:Mutation; D013045:Species Specificity
chemical_list: D003062:Codon; D004262:DNA Restriction Enzymes; D002262:Carboxy-Lyases; D006640:Histidine Decarboxylase