Weller J, Hill W E
Division of Biological Sciences, University of Montana, Missoula 59812.
Biochimie. 1991 Jul-Aug;73(7-8):971-81. doi: 10.1016/0300-9084(91)90138-q.
Interactions between Escherichia coli 16S rRNA sequences (as components of 30S ribosomal subunits or tight-couple 70S ribosomes) with the ligands poly(U), poly(AGU), tRNAPhe, tRNAfMet, and the initiation factors have been studied. The ligands were employed as competitors for selected sites on 16S rRNA known to be accessible for hybridization to cDNA oligomers, regions 517-528, 1397-1404, and 1534-1542. The binding of cDNAs 1534-1541 and 1398-1403 decreased in the presence of the ligand pair poly(U)/tRNAPhe. Only the binding of cDNA 1534-1541 was affected by poly(AGU), while none of the complementary DNA oligomer binding was affected by tRNAPhe or tRNAfMet alone. The poly(AGU)/tRNAfMet ligand pair caused an additional decline in the binding of cDNA 1534-1541, relative to that caused by poly(AGU) alone, but the ligand pair did not affect the binding of the cDNA oligomers 517-528 or 1398-1403. The inclusion of the initiation factors did not significantly alter the binding level decreases observed for cDNA 1534-1541 in the presence of mRNAs or tRNA. At the 517-528 and 1398-1403 regions, the inclusion of the initiation factors, in either the presence or absence of the other ligands, caused a large decrease in the binding of the cDNA oligomers. The oligomers complementary to 16S bases 517-528 and 1398-1403 did not bind to tight-couple or reassociated 70S ribosomes. The data are discussed in terms of the decoding site hypothesis, and in terms of the mRNA alignment mechanism proposed by Trifonov [1].
已对大肠杆菌16S rRNA序列（作为30S核糖体亚基或紧密偶联的70S核糖体的组成部分）与配体聚尿苷酸（poly(U)）、聚（AGU）、苯丙氨酸转运RNA（tRNAPhe）、甲酰甲硫氨酸转运RNA（tRNAfMet）以及起始因子之间的相互作用进行了研究。这些配体被用作已知可与cDNA寡聚体杂交的16S rRNA上选定位点（区域517 - 528、1397 - 1404和1534 - 1542）的竞争剂。在聚尿苷酸/苯丙氨酸转运RNA（poly(U)/tRNAPhe）配体对存在的情况下，cDNA 1534 - 1541和1398 - 1403的结合减少。只有cDNA 1534 - 1541的结合受聚（AGU）影响，而单独的苯丙氨酸转运RNA（tRNAPhe）或甲酰甲硫氨酸转运RNA（tRNAfMet）均不影响互补DNA寡聚体的结合。相对于单独的聚（AGU）所导致的情况，聚（AGU）/甲酰甲硫氨酸转运RNA（tRNAfMet）配体对使cDNA 1534 - 1541的结合进一步下降，但该配体对不影响cDNA寡聚体517 - 528或1398 - 1403的结合。起始因子的加入并未显著改变在存在信使RNA（mRNAs）或转运RNA（tRNA）的情况下观察到的cDNA 1534 - 1541结合水平的下降。在517 - 528和1398 - 1403区域，无论是否存在其他配体，起始因子的加入都会导致cDNA寡聚体的结合大幅下降。与16S碱基517 - 528和1398 - 1403互补的寡聚体不与紧密偶联或重新结合的70S核糖体结合。将根据解码位点假说以及特里福诺夫[1]提出的信使RNA比对机制对这些数据进行讨论。
