Crystal structure of human V-1 in the apo form.
Takeda, S., Koike, R., Nagae, T., Fujiwara, I., Narita, A., Maeda, Y., Ota, M.(2021) Acta Crystallogr F Struct Biol Commun 77: 13-21
- PubMed: 33439151 
- DOI: https://doi.org/10.1107/S2053230X20016829
- Primary Citation of Related Structures:  
7DF7 - PubMed Abstract: 
V-1, also known as myotrophin, is a 13 kDa ankyrin-repeat protein that binds and inhibits the heterodimeric actin capping protein (CP), which is a key regulator of cytoskeletal actin dynamics. The crystal structure of V-1 in complex with CP revealed that V-1 recognizes CP via residues spanning several ankyrin repeats. Here, the crystal structure of human V-1 is reported in the absence of the specific ligand at 2.3 Å resolution. In the asymmetric unit, the crystal contains two V-1 monomers that exhibit nearly identical structures (C α r.m.s.d. of 0.47 Å). The overall structures of the two apo V-1 chains are also highly similar to that of CP-bound V-1 (C α r.m.s.d.s of <0.50 Å), indicating that CP does not induce a large conformational change in V-1. Detailed structural comparisons using the computational program All Atom Motion Tree revealed that CP binding can be accomplished by minor side-chain rearrangements of several residues. These findings are consistent with the known biological role of V-1, in which it globally inhibits CP in the cytoplasm.
Organizational Affiliation: 
Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.