A Three-protein Charge Zipper Stabilizes a Complex Modulating Bacterial Gene Silencing.
J Biol Chem
; 290(35): 21200-12, 2015 Aug 28.
Article
em En
| MEDLINE
| ID: mdl-26085102
ABSTRACT
The Hha/YmoA nucleoid-associated proteins help selectively silence horizontally acquired genetic material, including pathogenicity and antibiotic resistance genes and their maintenance in the absence of selective pressure. Members of the Hha family contribute to gene silencing by binding to the N-terminal dimerization domain of H-NS and modifying its selectivity. Hha-like proteins and the H-NS N-terminal domain are unusually rich in charged residues, and their interaction is mostly electrostatic-driven but, nonetheless, highly selective. The NMR-based structural model of the complex between Hha/YmoA and the H-NS N-terminal dimerization domain reveals that the origin of the selectivity is the formation of a three-protein charge zipper with interdigitated complementary charged residues from Hha and the two units of the H-NS dimer. The free form of YmoA shows collective microsecond-millisecond dynamics that can by measured by NMR relaxation dispersion experiments and shows a linear dependence with the salt concentration. The number of residues sensing the collective dynamics and the population of the minor form increased in the presence of H-NS. Additionally, a single residue mutation in YmoA (D43N) abolished H-NS binding and the dynamics of the apo-form, suggesting the dynamics and binding are functionally related.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
/
Regulação Bacteriana da Expressão Gênica
/
Transferência Genética Horizontal
/
Proteínas de Ligação a DNA
/
Enterobacteriaceae
Limite:
Humans
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
França