Ribosome binding sequence site

Ribosomes Bacterial cells contain about 15,000 ribosomes. Each is composed of a small (SOS) subunit and a large (50S) subunit. The mass of a single ribosome is 2.3 X 10 daltons. It consists of 65% RNA and 35% protein. Ribosomes are the sites of protein synthesis. The mRNA binds to ribosomes, and the mRNA nucleotide sequence specifies the protein that is synthesized. 

Answer C. Incorporation of a Shine-Dalgarno sequence into the expression vector will promote ribosome binding to the translation start site on the mRNA produced by transcription of the cDNA insert. 

Figure 3 The nucleotide sequence and the deduced amino acid sequence of the S. aver-mitilis OMT gene. A potential ribosome binding site is in bold type and double-underlined. The stop codon is indicated by an asterisk. Conserved domains found in methyltransferases are underlined.

Shine-Dalgarno sequence (ribosome binding site) Initiation codon... 

Translation Initiation Site. In eukaryotes, if the transcription start site is known, and there is no intron interrupting the 5 UTR, Kozak s rule (Kozak, 1996) probably will locate the correct initiation codon in most cases. Splicing is normally absent in prokaryotes, yet because of the existence of multicitronic operons, promoter location is not the key information. Rather, the key is reliable localization of the ribosome binding site. The TATA sequence about 30 bp from the transcription start site may be used as a possible resource. 

The context of the mRNA sequence around the AUG codon translational start site, where the ribosome initiates translation of protein synthesis, is an important consideration. An appropriate consensus ribosome-binding region for the host organism should be used and potentially inhibitory RNA secondary structure, that may affect the ability of the ribosome to access this translation start site, avoided. Various RNA structure prediction programs such as... 

The features of the ribosome display construct are summarized in Figure 3. On the DNA level, the construct requires a T7 promoter for efficient in vitro transcription to mRNA. On the mRNA level, the construct contains, as a regulatory sequence for translation, either a prokaryotic ribosome binding site (Shine and Dalgamo, 1975) if the E. coli... 

Polysomes form as the result of the loading of sequential ribosomes at the 5 end of mRNA such that many ribosomes are progressing through a single mRNA at any one time. Clearly, polysomes do form in eukaryotes. Once the first ribosome has moved a significant distance from the ribosome binding site, there is no reason why a subsequent one should not be loaded through the normal sequence of events. 

Fig. 4 Plasmids for the intracellular production of tagged proteins in B. megaterium. All plasmids of the series 1622 are based on the shuttle vector pSTOP1522 (Fig. 3). (a) DNA sequence of ribosome binding site (RBS) and multiple cloning site (MCS) of the expression plasmid pSTOP1622. The...

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