Search

The case of the convergent loss of the D-hairpin in mitochondrial cysteine tRNA of the nine-banded armadillo Dasypus novemcinctus is described. This evolutionary event sheds light on the molecular structure-function relationship and on the effect of this relationship on the processes of evolution of biopolymers and macromolecules.

The sequence analysis of proteins and mitochondrial tRNA indicated that substitutions inducing the pathogenesis in humans often occur in normal individuals of other species having no signs of pathology. The analysis of the structural stability of the protein and tRNA molecules showed that the harmful effect of pathogenic substitutions is often neutralized by other compensatory substitutions, which restore the required normal stability of the structure. A further study of this phenomenon will probably lead to new methods of treatment of genetic pathology, which would be based not on the correction of one substitution but on the correction of the stability of the molecule as an entire functional unit.