MutS functions as a clamp loader by positioning MutL on the DNA during mismatch repair.
Nat Commun
; 13(1): 5808, 2022 10 03.
Article
en En
| MEDLINE
| ID: mdl-36192430
ABSTRACT
Highly conserved MutS and MutL homologs operate as protein dimers in mismatch repair (MMR). MutS recognizes mismatched nucleotides forming ATP-bound sliding clamps, which subsequently load MutL sliding clamps that coordinate MMR excision. Several MMR models envision static MutS-MutL complexes bound to mismatched DNA via a positively charged cleft (PCC) located on the MutL N-terminal domains (NTD). We show MutL-DNA binding is undetectable in physiological conditions. Instead, MutS sliding clamps exploit the PCC to position a MutL NTD on the DNA backbone, likely enabling diffusion-mediated wrapping of the remaining MutL domains around the DNA. The resulting MutL sliding clamp enhances MutH endonuclease and UvrD helicase activities on the DNA, which also engage the PCC during strand-specific incision/excision. These MutS clamp-loader progressions are significantly different from the replication clamp-loaders that attach the polymerase processivity factors ß-clamp/PCNA to DNA, highlighting the breadth of mechanisms for stably linking crucial genome maintenance proteins onto DNA.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Proteínas de Escherichia coli
/
Reparación de la Incompatibilidad de ADN
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Nat Commun
Asunto de la revista:
BIOLOGIA
/
CIENCIA
Año:
2022
Tipo del documento:
Article