Bassel B A, Mills D R
Nucleic Acids Res. 1979;6(5):2003-16. doi: 10.1093/nar/6.5.2003.
Initiation complex formation between PP7 RNA and ribosomes of Pseudomonas aeruginosa and Escherichia coli has been investigated. The PP7 RNA fragments protected by both species of ribosome have been isolated, and their sequences have been determined. Only one binding sites is available on the intact PP7 RNA strand, and this site is recognized by ribosomes of both species. The PP7 RNA binding site is approximately 38 nucleotides long. It contains two AUG sequences and a purine-rich segment near the 5'-end that is complementary to segments near the 3'-ends of the 16S ribosomal RNA's of both P. aeruginosa and E. coli. In order to establish which of the AUG codons acts as the initiator, the H2N-terminal amino acid sequence of PP7 coat protein was determined. This sequence is compatible with the codon sequence following the second AUG codon. The extent of the reaction of PP7 RNA with E. coli ribosomes is greater than with P. aeruginosa ribosomes, but our results do not indicate a qualitative difference in the initial interaction between intact PP7 RNA and the ribosomes of either species.
对铜绿假单胞菌和大肠杆菌核糖体与PP7 RNA之间起始复合物的形成进行了研究。已分离出两种核糖体保护的PP7 RNA片段，并确定了它们的序列。完整的PP7 RNA链上只有一个结合位点，且该位点能被两种核糖体识别。PP7 RNA结合位点约38个核苷酸长。它包含两个AUG序列以及5'端附近富含嘌呤的片段，该片段与铜绿假单胞菌和大肠杆菌16S核糖体RNA 3'端附近的片段互补。为了确定哪个AUG密码子作为起始密码子，测定了PP7外壳蛋白的H2N端氨基酸序列。该序列与第二个AUG密码子后的密码子序列相符。PP7 RNA与大肠杆菌核糖体的反应程度大于与铜绿假单胞菌核糖体的反应程度，但我们的结果并未表明完整的PP7 RNA与任何一种核糖体之间的初始相互作用存在质的差异。
