| Title |
Structural basis of DNA target recognition by the B3 domain of Arabidopsis epigenome reader VAL1 / |
| Authors |
Sasnauskas, Giedrius ; Kauneckaitė, Kotryna ; Šikšnys, Virginijus |
| DOI |
10.1093/nar/gky256 |
| Full Text |
|
| Is Part of |
Nucleic acids research.. Oxford : Oxford University Press. 2018, vol. 46, no 8, p. 4316-4324.. ISSN 0305-1048. eISSN 1362-4962 |
| Keywords [eng] |
Arabidopsis ; DNA ; VAL1 |
| Abstract [eng] |
Arabidopsis thaliana requires a prolonged period of cold exposure during winter to initiate flowering in a process termed vernalization. Exposure to cold induces epigenetic silencing of the FLOWERING LOCUS C (FLC) gene by Polycomb group (PcG) proteins. A key role in this epigenetic switch is played by transcriptional repressors VAL1 and VAL2, which specifically recognize Sph/RY DNA sequences within FLC via B3 DNA binding domains, and mediate recruitment of PcG silencing machinery. To understand the structural mechanism of site-specific DNA recognition by VAL1, we have solved the crystal structure of VAL1 B3 domain (VAL1-B3) bound to a 12 bp oligoduplex containing the canonical Sph/RY DNA sequence 5-CATGCA-3/5-TGCATG-3. We find that VAL1-B3 makes H-bonds and van der Waals contacts to DNA bases of all six positions of the canonical Sph/RY element. In agreement with the structure, in vitro DNA binding studies show that VAL1-B3 does not tolerate substitutions at any position of the 5-TGCATG-3 sequence. The VAL1-B3-DNA structure presented here provides a structural model for understanding the specificity of plant B3 domains interacting with the Sph/RY and other DNA sequences. |
| Published |
Oxford : Oxford University Press |
| Type |
Journal article |
| Language |
English |
| Publication date |
2018 |
| CC license |
|
