title: The role of the codon first letter in the relationship between genomic GC content and protein amino acid composition.
abstract: Analysis of the statistical distribution of amino acid compositions within 22 protein families shows that a GC bias generally affects proteins with a variety of functions from the extreme thermophile Thermus. This results in evident enrichment in amino acids of the group L, V, A, P, R and G and underrepresentation of amino acids of the group I, M, F, S, T, C and W. The strong amino acid composition biases noted in Thermus proteins are not related to thermoadaptation; they were also found in mesophilic homologues encoded by GC-rich genes. The results of a comparative analysis on large samples of translated sequences from 30 organisms, representing the three major kingdoms of life and including extremophiles, indicate a universal correlation between the usage of particular amino acids and the genomic GC content. It is concluded that the codon first letter plays a dominant role in translating the genomic GC signature into protein amino acid composition and sequences.
authors: Laboratoire de Microbiologie, Université Libre de Bruxelles (ULB), Belgium.
authors: V
authors: V
authors: Wilquet
authors: M
authors: M
authors: Van de Casteele
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics*; D001105:Archaea / Q000737:chemistry / Q000235:genetics; D019843:Archaeal Proteins / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry*; D003062:Codon / Q000235:genetics*; D003596:Cytosine; D005798:Genes, Bacterial / Q000235:genetics*; D006147:Guanine; D010802:Phylogeny; D016008:Statistical Distributions; D013696:Temperature; D013824:Thermus / Q000737:chemistry* / Q000235:genetics / Q000254:growth & development
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D003062:Codon; D006147:Guanine; D003596:Cytosine