Non-base-contacting residues enable kaleidoscopic evolution of metazoan C2H2 zinc finger DNA binding.
Genome Biol
; 18(1): 167, 2017 09 06.
Article
em En
| MEDLINE
| ID: mdl-28877740
ABSTRACT
BACKGROUND:
The C2H2 zinc finger (C2H2-ZF) is the most numerous protein domain in many metazoans, but is not as frequent or diverse in other eukaryotes. The biochemical and evolutionary mechanisms that underlie the diversity of this DNA-binding domain exclusively in metazoans are, however, mostly unknown.RESULTS:
Here, we show that the C2H2-ZF expansion in metazoans is facilitated by contribution of non-base-contacting residues to DNA binding energy, allowing base-contacting specificity residues to mutate without catastrophic loss of DNA binding. In contrast, C2H2-ZF DNA binding in fungi, plants, and other lineages is constrained by reliance on base-contacting residues for DNA-binding functionality. Reconstructions indicate that virtually every DNA triplet was recognized by at least one C2H2-ZF domain in the common progenitor of placental mammals, but that extant C2H2-ZF domains typically bind different sequences from these ancestral domains, with changes facilitated by non-base-contacting residues.CONCLUSIONS:
Our results suggest that the evolution of C2H2-ZFs in metazoans was expedited by the interaction of non-base-contacting residues with the DNA backbone. We term this phenomenon "kaleidoscopic evolution," to reflect the diversity of both binding motifs and binding motif transitions and the facilitation of their diversification.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
DNA
/
Evolução Molecular
/
Dedos de Zinco CYS2-HIS2
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Genome Biol
Assunto da revista:
BIOLOGIA MOLECULAR
/
GENETICA
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Canadá