ISSN:
1432-1432
Keywords:
Amino acid substitution
;
Protein evolution
;
Conservation of secondary structure
;
Hydrophobicity
;
Bulk
;
Multidimensional scaling
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary It is commonly recognised that many evolutionary changes of amino acid sequence in proteins are conservative: a substitution of one amino acid residue for another has a far greater chance of being accepted if the two residues are similar in properties. Here we investigate what properties are most important in determining the similarity of two amino acids, from the evolutionary point of view. Our results confirm earlier observations that the hydrophobicity and the molecular bulk of the side chain tend to be conserved. More importantly they also show that evolutionary pressures favour the conservation of secondary structure, and that all these properties can be arranged in a two dimensional diagram in which distances well preserve the observed substitution frequencies between amino acids. These results were obtained by a multi-dimensional scaling technique; and are independent of any prior opinions about conserved properties. Thus, it is demonstrated that all relations of importance to single amino acid substitutions can be represented by a single figure, which is much more comprehensible and useful than the usual tabular representation of substitution frequencies. Such a figure conveniently portrays the “stereochemical code” for conservative substitution.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02300754
