Single-myb histone proteins from Arabidopsis thaliana: Quantitative study of telomere binding specificity and kinetics

Ctirad Hofr (1) , Pavla Šultesová , Michal Zimmermann , Iva Mozgová , Petra Procházková Schrumpfová , Michaela Wimmerová , Jiří Fajkus

1 Functional Genomics and Proteomics

Proteins that bind telomeric DNA modulate the structure of chromosome ends and control telomere function and maintenance. It has been shown that Arabidopsis thaliana AtTRB proteins from the single-myb-histone (SMH) family selectively bind double-stranded telomeric DNA and interact with the telomeric protein AtPOT1b, which is involved in telomere capping. Here we performed the first quantitative DNA binding study of this plant-specific family of proteins. Interactions of full-length proteins AtTRB1 and AtTRB3 with telomeric DNA were analyzed by electrophoretic mobility-shift assay, fluorescence anisotropy and surface plasmon resonance to reveal their binding stoichiometry and kinetics. Kinetic analyses at different salt conditions enabled us to estimate the electrostatic component of binding and explain different affinities of the two proteins to telomeric DNA. On the basis of available data, a putative model explaining the binding stoichiometry and the protein arrangement on telomeric DNA is presented.

Mots clés: Life Sciences

Ctirad Hofr, Pavla Šultesová, Michal Zimmermann, Iva Mozgová, Petra Procházková Schrumpfová, et al.. Single-myb histone proteins from Arabidopsis thaliana: Quantitative study of telomere binding specificity and kinetics. Biochemical Journal, 2009, 419 (1), pp.221-228. ⟨10.1042/BJ20082195⟩. ⟨hal-00479124⟩