Translocation properties of primitive molecular machines and their relevance to the structure of the genetic code |
| |
Authors: | Aldana-González M Cocho G Larralde H Martínez-Mekler G |
| |
Affiliation: | The James Franck Institute, The University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637-1467, USA. maximino@control.uchicago.edu |
| |
Abstract: | We address the question, related with the origin of the genetic code, of why are there three bases per codon in the translation to protein process. As a follow-up to our previous work (Aldana et al., 1998, Martínez-Mekler et al., 1999a,b), we approach this problem by considering the translocation properties of primitive molecular machines, which capture basic features of ribosomal/messenger RNA interactions, while operating under prebiotic conditions. Our model consists of a short one-dimensional chain of charged particles (rRNA antecedent) interacting with a polymer (mRNA antecedent) via electrostatic forces. The chain is subject to external forcing that causes it to move along the polymer which is fixed in a quasi-one-dimensional geometry. Our numerical and analytic studies of statistical properties of random chain/polymer potentials suggest that, under very general conditions, a dynamics is attained in which the chain moves along the polymer in steps of three monomers. By adjusting the model in order to consider present-day genetic sequences, we show that the above property is enhanced for coding regions. Intergenic sequences display a behavior closer to the random situation. We argue that this dynamical property could be one of the underlying causes for the three-base codon structure of the genetic code |
| |
Keywords: | |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|