Bioinformatics Centre, Bose Institute, C.I.T. Scheme VII M, Kolkata, India.
Gene. 2011 Aug 1;481(2):76-82. doi: 10.1016/j.gene.2011.04.009. Epub 2011 Apr 30.
Protein translation has been elucidated to be dictated by evolutionary constraints, namely, variations in tRNA availabilities and/or variations in codon-anticodon binding that is manifested in biased codon usage. Taking advantage of publicly available mRNA expression and protein abundance data for Saccharomyces cerevisiae, we have performed a comprehensive analysis of the diverse factors guiding translation leading to desired protein levels irrespective of the corresponding high or low mRNA levels. It has been elucidated in this study that different combinations of most abundant/non abundant tRNA isoacceptors are selected for in S. cerevisiae that helps in achieving the optimum speed and accuracy in the protein translation process. This is also accompanied by the strategic location of codon pairs in coherence to mRNA secondary structure folding stability for the above mentioned combinations of tRNA isoacceptors. We thus find that codon pair contextual effects; in addition to tRNA abundance and mRNA folding stability during translation elongation process play plausible roles in maintaining translation accuracy and speed that can achieve desired protein levels.
蛋白质翻译被阐明受进化限制的支配，即 tRNA 可用性的变化和/或密码子-反密码子结合的变化，这表现在密码子使用偏好上。利用酿酒酵母公开的 mRNA 表达和蛋白质丰度数据，我们对多种指导翻译的因素进行了全面分析，这些因素导致了所需的蛋白质水平，而不管相应的 mRNA 水平高低。本研究阐明了酿酒酵母中选择了不同组合的最丰富/非丰富的 tRNA 同工受体，这有助于在蛋白质翻译过程中实现最佳的速度和准确性。这也伴随着密码子对在与 mRNA 二级结构折叠稳定性相关的位置上的策略性组合，以适应上述 tRNA 同工受体的选择。因此，我们发现密码子对上下文效应；除了翻译延伸过程中 tRNA 丰度和 mRNA 折叠稳定性外，在维持翻译准确性和速度方面也起着合理的作用，从而达到所需的蛋白质水平。
