In addition to the wealth of sequence and structural data, we exploited the work of Sanbonmatsu et al. [20] on simulating movement of tRNAs in the ribosome.Reviewers' commentsReviewer's report 1Jerzy Jurka, Genetic Information Research InstituteDue to the complexity of the translation system, its origin and evolution is a notoriously difficult chicken-and-egg like problem.