Toschka H Y, Struck J C, Erdmann V A
Freie Universität Berlin, Institute für Biochemie, FRG.
Nucleic Acids Res. 1989 Jan 11;17(1):31-6. doi: 10.1093/nar/17.1.31.
The essential 4.5S RNA of Escherichia coli contains a structural motif, which is also present in RNAs from other organisms, i.e. Bacillus subtilis scRNA, Halobacterium halobium 7S RNA and eukaryotic 7SL RNAs. This suggests a common function in all organisms, which could be related to protein translocation, since 7SL RNA is essential for this process in eukaryotes. We have analysed the structure and expression of the 4.5S RNA gene from another gram-negative eubacterium, Pseudomonas aeruginosa. The single copy gene encodes a 113 nucleotides long RNA, which shares 75% sequence homology to the E. coli 4.5S RNA and also exhibits the completely conserved hairpin structure of the corresponding RNAs of B. subtilis and E. coli. Transcription initiates 24 nucleotides upstream from the mature 5' end and exceeds beyond the 4.5S RNA coding region. A distal open reading frame, similar to that described for E. coli, does not exist downstream from the P. aeruginosa 4.5S RNA gene.
大肠杆菌的必需4.5S RNA含有一种结构基序，其他生物体的RNA中也存在这种基序，即枯草芽孢杆菌的scRNA、嗜盐菌的7S RNA和真核生物的7SL RNA。这表明在所有生物体中都有一个共同的功能，这可能与蛋白质转运有关，因为7SL RNA在真核生物的这一过程中是必不可少的。我们分析了另一种革兰氏阴性真细菌铜绿假单胞菌的4.5S RNA基因的结构和表达。该单拷贝基因编码一种113个核苷酸长的RNA，它与大肠杆菌的4.5S RNA有75%的序列同源性，并且还具有枯草芽孢杆菌和大肠杆菌相应RNA完全保守的发夹结构。转录从成熟5'端上游24个核苷酸处开始，并延伸超过4.5S RNA编码区。铜绿假单胞菌4.5S RNA基因下游不存在类似于大肠杆菌中描述的远端开放阅读框。
