Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học quốc tế cung cấp cho các bạn kiến thức về ngành y đề tài: Indications that "codon boundaries" are physico-chemically defined and that protein-folding information is contained in the redundant exon bases | Theoretical Biology and Medical Modelling BioMed Central Research Open Access Indications that codon boundaries are physico-chemically defined and that protein-folding information is contained in the redundant exon bases Jan Charles Biro Address Homulus Foundation San Francisco CA 94 105 USA Email Jan Charles Biro - Corresponding author Published 07 August 2006 Received 16 December 2005 Theoretical Biology and Medical Modelling 2006 3 28 doi 1742-4682-3-28 Accepted 07 August 2006 This article is available from http content 3 1 28 2006 Biro licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background All the information necessary for protein folding is supposed to be present in the amino acid sequence. It is still not possible to provide specific ab initio structure predictions by bioinformatical methods. It is suspected that additional folding information is present in protein coding nucleic acid sequences but this is not represented by the known genetic code. Results Nucleic acid subsequences comprising the 1st and or 3rd codon residues in mRNAs express significantly higher free folding energy FFE than the subsequence containing only the 2nd residues p n 81 . This periodic FFE difference is not present in introns. It is therefore a specific physico-chemical characteristic of coding sequences and might contribute to unambiguous definition of codon boundaries during translation. The FFEs of the 1st and 3rd residues are additive which suggests that these residues contain a significant number of complementary bases and that may contribute to selection for local RNA secondary structures in coding regions. This periodic codon-related structure-formation of mRNAs .
