Structural and functional analysis of the symmetrical Type I restriction endonuclease R.EcoR124I(NT).
PLoS One
; 7(4): e35263, 2012.
Article
en En
| MEDLINE
| ID: mdl-22493743
ABSTRACT
Type I restriction-modification (RM) systems are comprised of two multi-subunit enzymes, the methyltransferase (â¼160 kDa), responsible for methylation of DNA, and the restriction endonuclease (â¼400 kDa), responsible for DNA cleavage. Both enzymes share a number of subunits. An engineered RM system, EcoR124I(NT), based on the N-terminal domain of the specificity subunit of EcoR124I was constructed that recognises the symmetrical sequence GAAN(7)TTC and is active as a methyltransferase. Here, we investigate the restriction endonuclease activity of R. EcoR124I(NT)in vitro and the subunit assembly of the multi-subunit enzyme. Finally, using small-angle neutron scattering and selective deuteration, we present a low-resolution structural model of the endonuclease and locate the motor subunits within the multi-subunit enzyme. We show that the covalent linkage between the two target recognition domains of the specificity subunit is not required for subunit assembly or enzyme activity, and discuss the implications for the evolution of Type I enzymes.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
ADN
/
Desoxirribonucleasas de Localización Especificada Tipo I
/
Escherichia coli
/
Metiltransferasas
Idioma:
En
Revista:
PLoS One
Asunto de la revista:
CIENCIA
/
MEDICINA
Año:
2012
Tipo del documento:
Article
País de afiliación:
Reino Unido