title: Leader peptide-mediated transcriptional attenuation of lysine biosynthetic gene cluster in Thermus thermophilus.
abstract: The molecular mechanism for regulation of the genes involved in the biosynthesis of amino acids is poorly identified in Thermus thermophilus. In this study, we analyzed the transcriptional control of the major lysine biosynthetic gene cluster in T. thermophilus. S1 nuclease mapping revealed that the transcription, which is repressed by lysine, starts at 111 bp, upstream of the translational start codon, ATG, for the homocitrate synthase (hcs) gene. The 5'-leader region of 111 bp carries a sequence that can encode a short peptide of 14 amino acids with tandem-arranged lysine residues in its sequence. The nucleotide sequence of the region suggests that the transcript can form complicated secondary structures. Deletion of most of the 5'-leader region or mutation of the tandem lysine codons suppressed the transcriptional repression by lysine. Mutation of the tandem codons from lysine to glutamine resulted in glutamine-dependent repression of the gene connected downstream, indicating that the leader peptide mediated the transcriptional attenuation of the gene expression. This is the first report demonstrating the transcriptional regulation of amino acid biosynthesis in T. thermophilus.
authors.affiliation: Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Taishi
authors.initials: T
authors.lastname: Tsubouchi
authors.forename: Reiko
authors.initials: R
authors.lastname: Mineki
authors.forename: Hikari
authors.initials: H
authors.lastname: Taka
authors.forename: Naoko
authors.initials: N
authors.lastname: Kaga
authors.forename: Kimie
authors.initials: K
authors.lastname: Murayama
authors.forename: Chiharu
authors.initials: C
authors.lastname: Nishiyama
authors.forename: Hisakazu
authors.initials: H
authors.lastname: Yamane
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Kuzuyama
authors.forename: Makoto
authors.initials: M
authors.lastname: Nishiyama
mesh_terms: D001412:Bacillus subtilis / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D001483:Base Sequence; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D008239:Lysine / Q000096:biosynthesis* / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D021382:Protein Sorting Signals / Q000235:genetics / Q000502:physiology*; D016963:Thermus thermophilus / Q000737:chemistry* / Q000235:genetics* / Q000502:physiology; D014158:Transcription, Genetic / Q000235:genetics*; D000519:alpha-Galactosidase / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; D021382:Protein Sorting Signals; D000519:alpha-Galactosidase; D008239:Lysine