The Functional Role of Conserved Sequences of 16S Ribosomal RNA in Protein Synthesis

A crucial feature of all ribosomes is the conserved nature of its structural organization. This is nowhere more evident than in the secondary structure of the RNA components. Nevertheless, extensive sequence conservation, at least for the small subunit RNA (16S in prokaryotes), is found only at three single-stranded regions (Noller, 1984). One of these sequences (518–533) is in the 5’-domain while the remaining two (1394–1408; 1492–1505) are in the 3’-minor domain (Fig. 1). All three regions have been implicated in tRNA binding and other protein synthesis functions (reviewed in Noller, 1991). For example, C1400 (XL in Fig. 1) which is located in the middle of the 1394–1408 sequence was shown to be at the decoding site of the ribosome (reviewed in Ofengand, et al., 1986; 1988).