Selection of the translation initiation site (TIS) is a crucial step during translation. In the 1980s Marylin Kozak performed key studies on vertebrate mRNAs to characterize the optimal TIS consensus sequence, the Kozak motif. Within this motif, conservation of nucleotides in crucial positions, namely a purine at -3 and a G at +4 (where the A of the AUG is numbered +1), is essential for TIS recognition. Ever since its characterization the Kozak motif has been regarded as the optimal sequence to initiate translation in all eukaryotes. We revisit here published in silico data on TIS consensus sequences, as well as experimental studies from diverse eukaryotic lineages, and propose that, while the -3A/G position is universally conserved, the remaining variability of the consensus sequences enables their classification as optimal, strong, and moderate TIS sequences.

中文翻译：

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真核生物中AUG起始密码子上下文的保守性和变异性。

翻译起始位点（TIS）的选择是翻译过程中的关键步骤。在1980年代，Marylin Kozak对脊椎动物mRNA进行了关键研究，以表征最佳TIS共有序列，即Kozak基序。在该基序内，关键位置核苷酸的保守性（即-3处的嘌呤和+4处的G（AUG的A编号为+1））对于TIS识别至关重要。自从其特征被鉴定以来，Kozak基序一直被认为是在所有真核生物中启动翻译的最佳序列。我们将重新访问此处发表的关于TIS共有序列的计算机模拟数据，以及来自各种真核细胞谱系的实验研究，并提出，虽然-3A / G位置是普遍保守的，但共有序列的其余可变性使其能够分类为最佳，强的，