For subunit vaccine, a eukaryotic cloning host is always used because the recombinant proteins produced by bacteria are nonglycosylated, and glycosylation is necessary for the proteins to be immunologically active.

TLS Online TPP Program

#Id: 7089

#Unit 3. Fundamental Processes

IF1 prevents tRNAs from binding to the portion of the small subunit that will become part of the A-site.

†IF2 is a GTPase that interacts with three key components of the initiation machinery: the small subunit, IF1, and the charged initiator tRNA (fMet-tRNAi f-Met). By interacting with these components, IF2 facilitates the association of fMet-tRNAi f-Met with the small subunit and prevents other charged tRNAs from associating with the small subunit.

† IF3 binds to the small subunit and blocks it from reassociating with a large subunit. Because initiation requires a free small subunit, the binding of IF3 is critical for a new cycle of translation. 

TLS Online TPP Program

#Id: 7090

#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 7091

#Unit 3. Fundamental Processes

binding by a ribosome, many prokaryotic ORFs contain a short sequence upstream (on the 5’ side) of the start codon called the ribosome binding site (RBS). This element is also referred to as a polypurine stretch Shine–Dalgarno sequence.

TLS Online TPP Program

#Id: 7092

#Unit 3. Fundamental Processes

It is complementary to a highly conserved sequence close to the 3’ end of 16S rRNA.

The rRNA sequence is the hexamer:

3’. . . U C C U C C . . . 5’

TLS Online TPP Program

#Id: 7093

#Unit 3. Fundamental Processes

 5’-AUGA-3’ is sequence between overlapping ORFs is known as translational coupling.

TLS Online TPP Program

#Id: 7094

#Unit 3. Fundamental Processes