The base composition of the human genes is correlated with the secondary structures of the encoded proteins

The analysis of a non-redundant set of human proteins, for which both the crystallographic structures and the corresponding gene sequences are available. show that bases at third codon position are non-uniformly distributed along the coding sequences. Significant compositional differences are found by comparing the gene regions corresponding to the different secondary structures of the proteins. Inter and intra-structure differences were most pronounced in the GC-richest genes. These results are not compatible with any proposed hypotheses based on a neutral process of formation/maintenance of the high GC(3) levels of the genes localized in the GC-richest isochores of the human genome. (C) 2002 Elsevier Science B.V. All rights reserved.