The relationship between synonymous codon usage and protein structure

The hypothesis that synonymous codon usage is related to protein three-dimensional structure is examined by investigating the correlation between synonymous codon usage and protein secondary structure. All except two codons in E, coli show the same secondary structural preference for alpha-helix, beta-strand or coil as that of amino acids to be encoded by the respective codons, while 17 codons show secondary structural bias in mammalian proteins. The results indicate that there is no significant correlation between synonymous codon usage and protein secondary structure in E, coli, but there is a correlation in mammals. It could be deduced that synonymous codons carry much less structural information in prokaryotes than in eukaryotes due to their divergent evolutionary mechanism. (C) 1998 Federation of European Biochemical Societies.