Bonchuk, A.N., Balagurov, K.I., Baradaran, R., Boyko, K.M., Sluchanko, N.N., Khrustaleva, A.M., Burtseva, A.D., Arkova, O.V., Khalisova, K.K., Popov, V.O., Naschberger, A., Georgiev, P.G. (2024). The Arthropoda-specific Tramtrack group BTB protein domains use previously unknown interface to form hexamers.  eLife 13(): e96832.

FBrf0260563

Research paper

BTB (bric-a-brack, Tramtrack, and broad complex) is a diverse group of protein-protein interaction domains found within metazoan proteins. Transcription factors contain a dimerizing BTB subtype with a characteristic N-terminal extension. The Tramtrack group (TTK) is a distinct type of BTB domain, which can multimerize. Single-particle cryo-EM microscopy revealed that the TTK-type BTB domains assemble into a hexameric structure consisting of three canonical BTB dimers connected through a previously uncharacterized interface. We demonstrated that the TTK-type BTB domains are found only in Arthropods and have undergone lineage-specific expansion in modern insects. The Drosophila genome encodes 24 transcription factors with TTK-type BTB domains, whereas only four have non-TTK-type BTB domains. Yeast two-hybrid analysis revealed that the TTK-type BTB domains have an unusually broad potential for heteromeric associations presumably through a dimer-dimer interaction interface. Thus, the TTK-type BTB domains are a structurally and functionally distinct group of protein domains specific to Arthropodan transcription factors.

PMC11426971 (PMC) (EuropePMC)