title: Genetic aspects of aromatic amino acid biosynthesis in Lactococcus lactis.
abstract: Polymerase chain reaction (PCR) primers designed from a multiple alignment of predicted amino acid sequences from bacterial aroA genes were used to amplify a fragment of Lactococcus lactis DNA. An 8 kb fragment was then cloned from a lambda library and the DNA sequence of a 4.4 kb region determined. This region was found to contain the genes tyrA, aroA, aroK, and pheA, which are involved in aromatic amino acid biosynthesis and folate metabolism. TyrA has been shown to be secreted and AroK also has a signal sequence, suggesting that these proteins have a secondary function, possibly in the transport of amino acids. The aroA gene from L. lactis has been shown to complement an E. coli mutant strain deficient in this gene. The arrangement of genes involved in aromatic amino acid biosynthesis in L. lactis appears to differ from that in other organisms.
authors: Institute of Food Research, Norwich Research Park, Colney, UK.
authors: H G
authors: HG
authors: Griffin
authors: M J
authors: MJ
authors: Gasson
mesh_terms: D051229:3-Phosphoshikimate 1-Carboxyvinyltransferase; D019883:Alkyl and Aryl Transferases; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000096:biosynthesis* / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D001483:Base Sequence; D002826:Chorismate Mutase; D017124:Conserved Sequence; D029968:Escherichia coli Proteins; D005492:Folic Acid / Q000378:metabolism; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D013294:Lactococcus lactis / Q000201:enzymology* / Q000235:genetics*; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes; D009876:Operon; D010649:Phenylalanine / Q000096:biosynthesis; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000096:biosynthesis; D011302:Prephenate Dehydratase; D011401:Promoter Regions, Genetic; D021382:Protein Sorting Signals; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012765:Shikimic Acid / Q000378:metabolism; D014166:Transferases / Q000096:biosynthesis; D014364:Tryptophan / Q000096:biosynthesis; D014443:Tyrosine / Q000096:biosynthesis
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; C071216:P-protein, E coli; D021382:Protein Sorting Signals; C076398:TyrA protein, Bacteria; D012765:Shikimic Acid; D014443:Tyrosine; D010649:Phenylalanine; D014364:Tryptophan; D005492:Folic Acid; D014166:Transferases; D019883:Alkyl and Aryl Transferases; D051229:3-Phosphoshikimate 1-Carboxyvinyltransferase; D017853:Phosphotransferases (Alcohol Group Acceptor); C022642:shikimate kinase; D011302:Prephenate Dehydratase; D002826:Chorismate Mutase