These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Deoxyribonucleic acid-directed in vitro synthesis of ilv-specific messenger ribonucleic acid by extracts of Escherichia coli K-12.
    Author: Smolin DE, Umbarger HE.
    Journal: J Bacteriol; 1974 Dec; 120(3):1238-48. PubMed ID: 4612011.
    Abstract:
    The synthesis of ilv-specific messenger ribonucleic acid (mRNA) by extracts of Escherichia coli K-12 has been demonstrated in a deoxyribonucleic acid (DNA)-dependent, coupled transcription-translation system. ilv-Specific mRNA was determined by hybridization either to double-stranded lambdacI857St68h80dilv DNA (lambdah80dilv DNA) immobilized on nitrocellulose filters or to its separate l and r strands in liquid. During conditions optimal for protein synthesis, slightly more than 6% of the total [(3)H]RNA synthesized by S-30 extracts of the threonine deaminase-negative strain CU5136 was ilv-specific. Of this RNA, nearly 30% was complementary to the l (correct) strand. Total ilv-specific mRNA synthesis in vitro was not affected by omission of valine or all 20 amino acids from the reaction mixture. Hybridization of ilv-specific mRNA made in vitro to the l strand of lambdah80dilv DNA was effectively reduced in the presence of unlabeled RNA extracted from an ilv derepressed strain but not from an ilv deletion strain. In a purified transcription system, employing commercial RNA polymerase, twofold more ilv-specific mRNA was synthesized than in the coupled system, but this increase was entirely due to greater transcription of the r (incorrect) strand. An S-30 extract prepared from a strain isogenic to strain CU5136 but derepressed for ilvA gene expression synthesized twofold more ilv-specific mRNA in the coupled system. The significance of these findings is discussed.
    [Abstract] [Full Text] [Related] [New Search]