RRC ID 857
著者 Yoshida M, Kashiwagi K, Kawai G, Ishihama A, Igarashi K.
タイトル Polyamines enhance synthesis of the RNA polymerase sigma 38 subunit by suppression of an amber termination codon in the open reading frame.
ジャーナル J Biol Chem
Abstract The mechanisms by which polyamines stimulate synthesis of the RNA polymerase sigma(38) subunit in Escherichia coli were studied. Polyamine stimulation was observed only in strains in which the 33rd codon of RpoS mRNA is a UAG termination codon instead of a CAG codon for glutamine in wild-type E. coli. Readthrough of the termination codon by Gln-tRNA(supE) was stimulated by polyamines. This stimulation was found to be caused by an increase in both the level of suppressor tRNA(supE) and the binding affinity of Gln-tRNA(supE) for ribosomes. The stimulatory effect was observed with a UAG termination codon but not with UGA and UAA codons. Readthrough of the UAG termination codon at the 270th amino acid position of RpoS mRNA was also stimulated by polyamines, indicating that polyamines stimulate readthrough of a UAG codon regardless of its location within the RpoS mRNA. When cell viability of an E. coli strain having a termination codon in the 33rd position of RpoS mRNA was compared using cells cultured with or without putrescine, it was higher in cells cultured with putrescine than in cells cultured without putrescine. The level of sigma(38) subunit in the cells cultured with putrescine was higher than that in cells cultured without putrescine on days 2, 4, and 8, but the level of sigma(70) subunit was almost the same in cells cultured with or without putrescine. These results confirm that elevated expression of the rpoS gene is important for cell viability at late stationary phase.
巻・号 277(40)
ページ 37139-46
公開日 2002-10-4
DOI 10.1074/jbc.M206668200
PII S0021-9258(18)36427-5
PMID 12147703
MeSH Base Sequence Codon, Terminator / genetics* DNA-Directed RNA Polymerases / genetics* Escherichia coli / drug effects Escherichia coli / enzymology Escherichia coli / genetics* Gene Expression Regulation, Bacterial / drug effects Gene Expression Regulation, Enzymologic / drug effects Kinetics Molecular Sequence Data Nucleic Acid Conformation Open Reading Frames* Polyamines / pharmacology* Protein Subunits RNA, Transfer, Amino Acyl / genetics Sigma Factor / genetics* Spermidine / pharmacology Suppression, Genetic
IF 4.238
引用数 38
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
原核生物(大腸菌) W3110