Final answer:
The Kozak sequence is essential for proper translation initiation in eukaryotic cells, with a consensus sequence of 5'-GCC(purine)CCAUGG-3' and particularly important bolded bases ensuring correct start codon recognition.
Step-by-step explanation:
The Kozak sequence is crucial for indicating the start codon in eukaryotic mRNA for translation. The most important features of the Kozak sequence are the nucleotides flanking the start AUG codon, specifically the consensus sequence 5'-GCC(purine)CCAUGG-3' with the most critical being the bolded bases. These sequences affect the efficiency of translation initiation by ensuring the ribosome identifies the correct start codon, which is vital for correct protein synthesis.
A strong Kozak sequence correlates with efficient translation, whereas variations can affect ribosomal binding and the initiation rate. Intron sequences and elements such as the poly-A sequence, Shine-Dalgarno sequence, and the TATA box play other roles in mRNA stability and transcription but do not directly influence the initiation of translation like the Kozak sequence.
Understanding sequence conservation and functionality, as observed in experiments detailed by research articles, highlights the significance of the Kozak sequence in maintaining proper expression of genes within a eukaryotic system.