Caniparoli Luca, Lombardo Pierangelo
International School for Advanced Studies (SISSA), via Bonomea 265, I-34136, Trieste, Italy.
International School for Advanced Studies (SISSA), via Bonomea 265, I-34136, Trieste, Italy and Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Trieste, Italy.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Jan;89(1):012712. doi: 10.1103/PhysRevE.89.012712. Epub 2014 Jan 21.
Protein translation is one of the most important processes in cell life, but despite being well-understood biochemically, the implications of its intrinsic stochastic nature have not been fully elucidated. In this paper we develop a microscopic and stochastic model which describes a crucial step in protein translation, namely the binding of the tRNA to the ribosome. Our model explicitly takes into consideration tRNA recharging dynamics, spatial inhomogeneity, and stochastic fluctuations in the number of charged tRNAs around the ribosome. By analyzing this nonequilibrium system we are able to derive the statistical distribution of the times needed by the tRNAs to bind to the ribosome, and to show that it deviates from an exponential due to the coupling between the fluctuations of charged and uncharged populations of tRNA.
蛋白质翻译是细胞生命中最重要的过程之一，尽管从生物化学角度已被充分理解，但其内在随机性本质的影响尚未得到充分阐明。在本文中，我们开发了一个微观随机模型，该模型描述了蛋白质翻译中的一个关键步骤，即tRNA与核糖体的结合。我们的模型明确考虑了tRNA再充电动力学、空间不均匀性以及核糖体周围带电tRNA数量的随机波动。通过分析这个非平衡系统，我们能够推导出tRNA与核糖体结合所需时间的统计分布，并表明由于带电和不带电tRNA群体波动之间的耦合，该分布偏离指数分布。
