An hypothesis for explaining the mechanism of translocation in peptide chain synthesis.

A mechanism is proposed for mRNA translocation during peptide chain synthesis, which involves a reciprocal rotation of the two ribosomal components on each other in such a way as to propel the mRNA along a string of ribosomes on an endoplasmic reticulum membrane or to propel a single ribosome along an mRNA molecule in a membrane-free system. Release of tRNA's is assumed to occur from only one of the two ribosomal components at a time, so that there is no danger of loss of the tRNA's during peptide chain synthesis. The mechanism would make the ribosome an active, dynamic structure in addition to being a platform with catalytic activity which holds the components of peptide chain synthesis in juxtaposition.