The main function of ribosome is to serve as a site of mRNA translation into a sequence of amino acids in a process called protein biosynthesis. Most important for understanding the translational mechanism is how a ribosome interacts with the factors playing role in this complicated cellular process. The key elements of these interactions are the functional domains of rRNAs. In this paper, we present the functional importance of 23S rRNA in polypeptide biosynthesis.