Identification of an atypical interaction site in the BTB domain of the MYC-interacting zinc-finger protein 1.
Orth, B., Sander, B., Moglich, A., Diederichs, K., Eilers, M., Lorenz, S.(2021) Structure 29: 1230-1240.e5
- PubMed: 34186024 
- DOI: https://doi.org/10.1016/j.str.2021.06.005
- Primary Citation of Related Structures:  
7AZW, 7AZX - PubMed Abstract: 
The repurposing of structurally conserved protein domains in different functional contexts is thought to be a driving force in the evolution of complex protein interaction networks. The BTB/POZ domain is such a versatile binding module that occurs over 200 times in the human proteome with diverse protein-specific adaptations. In BTB-zinc-finger transcription factors, the BTB domain drives homo- and heterodimerization as well as interactions with non-BTB-domain-containing proteins. Which mechanisms encode specificity in these interactions at a structural level is incompletely understood. Here, we uncover an atypical peptide-binding site in the BTB domain of the MYC-interacting zinc-finger protein 1 (MIZ1) that arises from local flexibility of the core BTB fold and may provide a target site for MIZ1-directed therapeutic approaches. Intriguingly, the identified binding mode requires the BTB domain to be in a homodimeric state, thus holding opportunities for functional discrimination between homo- and heterodimers of MIZ1 in the cell.
Organizational Affiliation: 
Rudolf Virchow Center for Integrative and Translational Bioimaging, University of Würzburg, 97080 Würzburg, Germany; Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.