Synergism of the Two Myb Domains of Tay1 Protein Results in High Affinity Binding to Telomeres*

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Authors	VISACKA Katarina HOFR Ctirad WILLCOX Smaranda NEČASOVÁ Ivona PAVLOUŠKOVÁ Jana SEPSIOVA Regina WIMMEROVÁ Michaela SIMONICOVA Lucia NOSEK Jozef FAJKUS Jiří GRIFFITH Jack D. TOMASKA Lubomir
Year of publication	2012
Type	Article in Periodical
Magazine / Source	The Journal of Biological Chemistry
MU Faculty or unit	Central European Institute of Technology
Citation
Web	http://www.ncbi.nlm.nih.gov/pubmed/22815473
Doi	http://dx.doi.org/10.1074/jbc.M112.385591
Field	Biochemistry
Keywords	DNA-BINDING; ARABIDOPSIS-THALIANA; COMPLEX; TRF1; IDENTIFICATION; RECOGNITION; SPECIFICITY; PROTECTION; EVOLUTION; GENOME
Attached files	2012_JBC_Visacka.pdf
Description	Double-stranded regions of the telomeres are recognized by proteins containing Myb-like domains conferring specificity toward telomeric repeats. Although biochemical and structural studies revealed basic molecular principles involved in DNA binding, relatively little is known about evolutionary pathways leading to various types of Myb domain-containing proteins in divergent species of eukaryotes. Recently we identified a novel type of telomere-binding protein YlTay1p from the yeast Yarrowia lipolytica containing two Myb domains (Myb1, Myb2) very similar to the Myb domain of mammalian TRF1 and TRF2. In this study we prepared mutant versions of YlTay1p lacking Myb1, Myb2, or both Myb domains and found that YlTay1p carrying either Myb domain exhibits preferential affinity to both Y. lipolytica (GGGTTAGTCA)n and human (TTAGGG)n telomeric sequences. Quantitative measurements of the protein binding to telomeric DNA revealed that the presence of both Myb domains is required for a high affinity of YlTay1p to either telomeric repeat. Additionally, we performed detailed thermodynamic analysis of the YlTay1p interaction with its cognate telomeric DNA, which is to our knowledge the first energetic description of a full-length telomeric-protein binding to DNA. Interestingly, when compared with human TRF1 and TRF2 proteins, YlTay1p exhibited higher affinity not only for Y. lipolytica telomeres but also for human telomeric sequences. The duplication of the Myb domain region in YlTay1p thus produces a synergistic effect on its affinity toward the cognate telomeric sequence, alleviating the need for homodimerization observed in TRF-like proteins possessing a single Myb domain.
Related projects:	CEITEC - Central European Institute of Technology Dynamika vzniku shelterinového komplexu