RRC ID 33588
著者 Yoshida K, Miwa Y, Ohmori H, Fujita Y.
タイトル Analysis of an insertional operator mutation (gntOi) that affects the expression level of the Bacillus subtilis gnt operon, and characterization of gntOi suppressor mutations.
ジャーナル Mol Gen Genet
Abstract The Bacillus subtilis gnt operon is negatively regulated via interaction of the gnt repressor (GntR) with an operator upstream of gntR, which is antagonized by gluconate. An 8 bp insertional operator mutation (gntOi) of the gnt operon was constructed which affected the expression level of this operon. Two suppressors of this gntOi mutation, exhibiting normal expression, were also isolated; one involved a threonine substitution for the Ala-48 residue (gntR48T) within the helix-turn-helix DNA-binding motif of GntR, and the other an adenine substitution for the guanine at nucleotide -4 within the gntOi operator (gntOiM4A) (+ 1 is the transcription initiation site). The gntR48T mutation by itself rendered the gnt operon partially constitutive. When the gntR43L mutation, which renders the gnt operon fully constitutive, was introduced into the gntOi or gntOiM4A mutant, the operator mutations were found not to affect the promoter activity of the gnt operon. These in vivo results indicate that the gntOi mutation affects the operator interaction with GntR, causing a low expression level even in the presence of gluconate. In vitro gel retardation and DNase I footprint analyses demonstrated that even when gluconate was present, GntR still bound to the gntOi operator region.
巻・号 248(5)
ページ 583-91
公開日 1995-9-20
DOI 10.1007/BF02423454
PMID 7476858
MeSH Amino Acid Sequence Bacillus subtilis / genetics* Base Sequence DNA Transposable Elements / genetics DNA-Binding Proteins / genetics* Escherichia coli Proteins* Gene Expression Regulation, Bacterial Molecular Sequence Data Plasmids Repressor Proteins / genetics* Sequence Alignment Sequence Analysis Suppression, Genetic Transcription Factors*
引用数 8
WOS 分野 GENETICS & HEREDITY BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
原核生物(枯草菌) MBS151 MBS152 MBS153 MBS163 MBS166