What sequence is used in prokaryotes to initiate translation?

The Shine-Dalgarno sequence is a crucial component in prokaryotic translation initiation. This sequence is located upstream of the start codon (AUG) in the mRNA and serves to align the ribosome with the mRNA for proper translation. It is recognized by the 16S rRNA of the small ribosomal subunit (30S) in bacteria. The complementary base pairing between the Shine-Dalgarno sequence and the rRNA promotes the correct positioning of the ribosome at the start codon, ensuring that translation begins accurately.

In contrast, the Kozak sequence, relevant to eukaryotic initiation of translation, surrounds the start codon and helps in the recognition of the AUG start codon in eukaryotic mRNA. The AUG sequence itself signifies the start codon for translation but does not play a role in the ribosome's attachment to the mRNA in prokaryotes. The CAP sequence is a modification found in eukaryotic mRNA that facilitates translation initiation but is not present in prokaryotic systems. Thus, the Shine-Dalgarno sequence is the correct answer for prokaryotic translation initiation due to its specific function in guiding the ribosome.