Gurevich A I, Esipov R S, Kachalina T A, Kaiushin A L, Korosteleva M D
Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.
Bioorg Khim. 1997 Nov;23(11):888-94.
Potential sites of the complementary interaction of the translation initiation region (TIR) with 16S rRNA are revealed, and the role of these sites in the gene expression level is studied. The high expression level of a gene depends not only on the complementary interaction of TIR with 16S rRNA in sites proximal to the start codon [anti-Shine-Dalgarno (ASD) (delta G > -8 to -10 kcal/mol) and downstream box (DB)] and located at the -15 to +20 mRNA region but also on complementary interactions in distal sites of the untranslated branch of TIR (mTIR). Among them, the UB (upsteam box) 1 site, complementarily interacting with the exposed 452-490 segment of the 440-490 loop of 16S rRNA, may be located in the -15 to -50 mTIR segment. In the -50 to -70 mTIR segment may be located UB2 and UB3 sites, which interact with the exposed segment 478-488 of the 440-490 loop and segment 520-532 of the 520-540 loop of 16S rRNA, the UB3 site being much more efficacious. The high expression level requires that the total free energy of complementary interactions of UB1, UB2, and UB3 sites with 16S rRNA exceeds -20 kcal/mol.
揭示了翻译起始区域（TIR）与16S rRNA互补相互作用的潜在位点，并研究了这些位点在基因表达水平中的作用。基因的高表达水平不仅取决于TIR与起始密码子近端位点[反Shine-Dalgarno（ASD）（ΔG > -8至-10 kcal/mol）和下游框（DB）]中16S rRNA的互补相互作用，且这些位点位于-15至+20 mRNA区域，还取决于TIR非翻译分支（mTIR）远端位点的互补相互作用。其中，与16S rRNA的440-490环的暴露452-490片段互补相互作用的UB（上游框）1位点，可能位于-15至-50 mTIR片段中。在-50至-70 mTIR片段中可能存在UB2和UB3位点，它们分别与16S rRNA的440-490环的暴露片段478-488以及520-540环的片段520-532相互作用，其中UB3位点的作用更为显著。高表达水平要求UB1、UB2和UB3位点与16S rRNA互补相互作用的总自由能超过-20 kcal/mol。
