Premium
ANOTHER LOOK AT THE MOLECULAR VARIABILITY OF H‐2 GENE PRODUCTS
Author(s) -
Lengerová Alena,
Matouŝek V.
Publication year - 1979
Publication title -
international journal of immunogenetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.41
H-Index - 47
eISSN - 1744-313X
pISSN - 1744-3121
DOI - 10.1111/j.1744-313x.1979.tb00688.x
Subject(s) - amino acid , genetic code , genetics , gene , biology , intraspecific competition , allele , molecular evolution , genetic variation , phylogenetics , ecology
Summary An attempt was made to characterize the amino acid interchanges in the presumably allelic products of MHC (H‐2 and HLA) as revealed by the results published so far of microsequencing analysis of their 20‐30 N‐terminal positions. The distances between interchanged amino acids were judged by several criteria: the Sneath's and Grantham's indices, the classification of the substitutions as intra‐versus intergroup (i.e. groups of chemically related amino acids), the minimum number and type of underlying base substitutions according to the genetic code. The detected variation was also compared to that in highly variable (fibrinopeptides A and B) and highly conservative (histone IV) amino acid sequences. A selection of human haemoglobin α‐chain variants, without known pathological effects, was further used as a standard of reference for intraspecific ‘permissible variation'. The results of these comparisons do not prove, but are not incompatible with, the idea that the function of the H‐2 (HLA) fragment displaying the observed molecular variability, does not impose too rigid a constraint on its structure. Considerably different amino acid sequences might represent functionally more or less equivalent compromises due to neutral mutations which fall into the category of ‘evolutionary noise’ at the molecular level.