Crystal structure of the endonuclease domain encoded by the telomere-specific long interspersed nuclear element, TRAS1
Maita, N., Anzai, T., Aoyagi, H., Mizuno, H., Fujiwara, H.(2004) J Biol Chem 279: 41067-41076
- PubMed: 15247245 
- DOI: https://doi.org/10.1074/jbc.M406556200
- Primary Citation of Related Structures:  
1WDU - PubMed Abstract: 
The telomere-specific long interspersed nuclear element, TRAS1, encodes an endonuclease domain, TRAS1-EN, which specifically cleaves the telomeric repeat targets (TTAGG)n of insects and (TTAGGG)n of vertebrates. To elucidate the sequence-specific recognition properties of TRAS1-EN, we determined the crystal structure at 2.4-A resolution. TRAS1-EN has a four-layered alpha/beta sandwich structure; its topology is similar to apurinic/apyrimidinic endonucleases, but the beta-hairpin (beta10-beta11) at the edge of the DNA-binding surface makes an extra loop that distinguishes TRAS1-EN from cellular apurinic/apyrimidinic endonucleases. A protein-DNA complex model suggests that the beta10-beta11 hairpin fits into the minor groove, enabling interaction with the telomeric repeats. Mutational studies of TRAS1-EN also indicated that the Asp-130 and beta10-beta11 hairpin structure are involved in specific recognition of telomeric repeats.
Organizational Affiliation: 
Department of Biochemistry, National Institute of Agrobiological Sciences, Tsukuba, 305-8602, Japan.