title: Crystal structure of a tankyrase 1-telomere repeat factor 1 complex.
abstract: Telomere repeat factor 1 (TRF1) is a subunit of shelterin (also known as the telosome) and plays a critical role in inhibiting telomere elongation by telomerase. Tankyrase 1 (TNKS1) is a poly(ADP-ribose) polymerase that regulates the activity of TRF1 through poly(ADP-ribosyl)ation (PARylation). PARylation of TRF1 by TNKS1 leads to the release of TRF1 from telomeres and allows telomerase to access telomeres. The interaction between TRF1 and TNKS1 is thus important for telomere stability and the mitotic cell cycle. Here, the crystal structure of a complex between the N-terminal acidic domain of TRF1 (residues 1-55) and a fragment of TNKS1 covering the second and third ankyrin-repeat clusters (ARC2-3) is presented at 2.2 Å resolution. The TNKS1-TRF1 complex crystals were optimized using an `oriented rescreening' strategy, in which the initial crystallization condition was used as a guide for a second round of large-scale sparse-matrix screening. This crystallographic and biochemical analysis provides a better understanding of the TRF1-TNKS1 interaction and the three-dimensional structure of the ankyrin-repeat domain of TNKS.
authors.affiliation: College of Life Sciences, Nankai University, Weijin Road #94, Tianjin 300071, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.affiliation: College of Life Sciences, Nankai University, Weijin Road #94, Tianjin 300071, People's Republic of China.
authors.forename: Ruihong
authors.initials: R
authors.lastname: Qiao
authors.affiliation: Department of Biological Structure, University of Washington, 1959 NE Pacific Street, Seattle, Washington 98195, USA.
authors.forename: Zhizhi
authors.initials: Z
authors.lastname: Wang
authors.affiliation: College of Life Sciences, Nankai University, Weijin Road #94, Tianjin 300071, People's Republic of China.
authors.forename: Weihong
authors.initials: W
authors.lastname: Zhou
authors.affiliation: College of Life Sciences, Nankai University, Weijin Road #94, Tianjin 300071, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Biological Structure, University of Washington, 1959 NE Pacific Street, Seattle, Washington 98195, USA.
authors.forename: Wenqing
authors.initials: W
authors.lastname: Xu
authors.affiliation: College of Life Sciences, Nankai University, Weijin Road #94, Tianjin 300071, People's Republic of China.
authors.forename: Zihe
authors.initials: Z
authors.lastname: Rao
mesh_terms: D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D038501:Tankyrases / Q000737:chemistry*; D016615:Telomere
chemical_list: D038501:Tankyrases
keywords: PARylation; TNKS; TRF1; complex structure; tankyrase; telomere; telomere repeat factor 1