Traffic of interacting ribosomes on mRNA during protein synthesis: effects of chemo-mechanics of individual ribosomes

Many {\it ribosomes} simultaneously move on the same messenger RNA (mRNA), each synthesizing separately a copy of the same protein. In contrast to the earlier models, here {\it we develop a ``unified'' theoretical model} that not only incorporates the {\it mutual exclusions} of the interacting ribosomes, but also describes explicitly the mechano-chemistry of each of these macromolecular machines during protein synthesis. Using analytical and numerical techniques of non-equilibrium statistical mechanics, we analyze the rates of protein synthesis and the spatio-temporal organization of the ribosomes in this model. We also predict how these properties would change with the changes in the rates of the various chemo-mechanical processes in each ribosome. Finally, we illustrate the power of this model by making experimentally testable predictions on the rates of protein synthesis and the density profiles of the ribosomes on some mRNAs in {\it E-coli}.