Figure 1.

Structures of hCap2_HR1.A, two copies of hCap2_HR1 forms a dimer with the overall structure roughly resembling the shape of a pair of "scissors," which could be divided into two subdomains: a "blade"-like N-lobe and a "bow"-like C-lobe. B, the N-lobe of hCap2_HR1, when compared to the C-lobe, exhibits higher B factors, especially in its antiparallel helix-loop-helix region. C, part of the human Caprin-2 HR1 domain has been previously resolved by Wu et al. (PDB code: 5J97), which roughly corresponds to the "bow" part of hCap2_HR1. D, the most homologous protein three dimensionally for the N-lobe of hCap2_HR1 is flagellar FliJ protein (PDB code: 3ajw). FliJ forms an anti-parallel, α-helical coiled-coil structure. E, superimposition of FliJ with hCap2_HR1 chain A or chain B shows a limited similarity between these two structures. Images of structures were generated using PyMOL (https://pymol.org/). HR, homologous region.