Fig. 2
From: Structural basis of meiotic telomere attachment to the nuclear envelope by MAJIN-TERB2-TERB1
Crystal structure of MAJINCore-TERB2C. a, b Crystal structure of MAJINCore-TERB2C (sequences truncated to amino acids 1–106 and 168–207) solved in C2221 spacegroup at 1.85 Å resolution, demonstrating a 2:2 heterotetrameric complex shown as (a) cartoon representation and (b) molecular surface of MAJIN with cartoon representation of TERB2 chains. MAJIN forms a central globular dimer that is encircled by two TERB2 chains. c, d Cartoon representations and (e) topology diagram of a single MAJIN–TERB2 protomer. MAJIN adopts a β-grasp fold in which a β-sheet grasps around a central α-helix in a β(2)-α-β(3) configuration, with an additional two-stranded β-sheet appendage inserted between β4 and β7. The TERB2 chain wraps around the exposed surface of the α-helix to complete its closure such that it becomes fully encircled by TERB2 and the grasping β-sheet. f, g The MAJIN–TERB2 interface spans an area of approximately 1300 Å2 for each protomer. f The N-terminal end of TERB2C wraps around the central MAJIN α-helix with aromatic and hydrophobic residues packing into pockets on the MAJIN surface. g The C-terminal end of TERB2C provides a short β-strand extension to the grasping β-sheet, a salt bridge between D191 (TERB2) and R14 (MAJIN), a structural wedge (formed by F192, P194 and Y199) between the grasping and appendage β-sheets of MAJIN, and a β-strand extension to the β-sheet appendage. h The MAJIN–TERB2 dimerization interface contains approximately 650 Å2 of buried surface area, formed of largely aromatic and hydrophobic interactions between P64, F73, Y75 and Y104 (MAJIN), and Y176 (TERB2)
