Mutations in the Shine-Dalgarno sequence can reduce translation. This reduction is due to a reduced mRNA-ribosome pairing efficiency, as evidenced by the fact that complementary mutations in the anti-Shine-Dalgarno sequence can restore translation.
When the Shine-Dalgarno sequence and the anti-Shine-Dalgarno sequence pair, the translation initiation factors IF2-GTP, IF1, IF3, as well as the initiator tRNA fMet-tRNA(fMET) are recruited to the ribosome.
In Gram-negative bacteria, the presence of a Shine-Dalgarno sequence is not obligatory for the ribosome to locate the initiator codon. For example, it has been shown that deletion of Anti-Shine-Dalgarno sequence from 16S rRNA doesn't lead to translation initiation at non-authentic sites. Moreover, numerous prokaryotic mRNAs don't possess Shine-Dalgarno sequences at all. What principally attracts ribosome to mRNA initiation region is apparently ribosomal protein S1, which binds to AU-rich sequences found in many prokaryotic mRNAs 15-30 nucleotides upstream of start-codon. It should be noted, that S1 is only present in Gram-negative bacteria, being absent from Gram-positive species.
Study Results from Institute of Genetics and Developmental Biology Provide New Insights into Antimicrobial Cationic Peptides
Feb 26, 2013; By a News Reporter-Staff News Editor at Life Science Weekly -- Research findings on Peptides are discussed in a new report....