SUMO-1 regulates the conformational dynamics of thymine-DNA Glycosylase regulatory domain and competes with its DNA binding activity.
BMC Biochem
; 12: 4, 2011 Feb 01.
Article
en En
| MEDLINE
| ID: mdl-21284855
BACKGROUND: The human thymine-DNA glycosylase (TDG) plays a dual role in base excision repair of G:U/T mismatches and in transcription. Regulation of TDG activity by SUMO-1 conjugation was shown to act on both functions. Furthermore, TDG can interact with SUMO-1 in a non-covalent manner. RESULTS: Using NMR spectroscopy we have determined distinct conformational changes in TDG upon either covalent sumoylation on lysine 330 or intermolecular SUMO-1 binding through a unique SUMO-binding motif (SBM) localized in the C-terminal region of TDG. The non-covalent SUMO-1 binding induces a conformational change of the TDG amino-terminal regulatory domain (RD). Such conformational dynamics do not exist with covalent SUMO-1 attachment and could potentially play a broader role in the regulation of TDG functions for instance during transcription. Both covalent and non-covalent processes activate TDG G:U repair similarly. Surprisingly, despite a dissociation of the SBM/SUMO-1 complex in presence of a DNA substrate, SUMO-1 preserves its ability to stimulate TDG activity indicating that the non-covalent interactions are not directly involved in the regulation of TDG activity. SUMO-1 instead acts, as demonstrated here, indirectly by competing with the regulatory domain of TDG for DNA binding. CONCLUSIONS: SUMO-1 increases the enzymatic turnover of TDG by overcoming the product-inhibition of TDG on apurinic sites. The mechanism involves a competitive DNA binding activity of SUMO-1 towards the regulatory domain of TDG. This mechanism might be a general feature of SUMO-1 regulation of other DNA-bound factors such as transcription regulatory proteins.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteína SUMO-1
/
Timina ADN Glicosilasa
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
BMC Biochem
Asunto de la revista:
BIOQUIMICA
Año:
2011
Tipo del documento:
Article
País de afiliación:
Francia
Pais de publicación:
Reino Unido