3m52
Crystal structure of the BTB domain from the Miz-1/ZBTB17 transcription regulator
Structural highlights
FunctionZBT17_HUMAN Plays a critical role in early lymphocyte development, where it is essential to prevent apoptosis in lymphoid precursors, allowing them to survive in response to IL7 and undergo proper lineage commitment (By similarity). Transcription factor that can function as an activator or repressor depending on its binding partners, and by targeting negative regulators of cell cycle progression. Has been shown to bind to the promoters of adenovirus major late protein and cyclin D1 and activate transcription. Required for early embryonic development during gastrulation.[1] [2] [3] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe BTB domain is a widely distributed protein-protein interaction motif that is often found at the N-terminus of zinc finger transcription factors. Previous crystal structures of BTB domains have revealed tightly interwound homodimers, with the N-terminus from one chain forming a two-stranded anti-parallel beta-sheet with a strand from the other chain. We have solved the crystal structures of the BTB domains from Fanconi anemia zinc finger (FAZF) and Miz1 (Myc-interacting zinc finger 1) to resolutions of 2.0 A and 2.6 A, respectively. Unlike previous examples of BTB domain structures, the FAZF BTB domain is a nonswapped dimer, with each N-terminal beta-strand associated with its own chain. As a result, the dimerization interface in the FAZF BTB domain is about half as large as in the domain-swapped dimers. The Miz1 BTB domain resembles a typical swapped BTB dimer, although it has a shorter N-terminus that is not able to form the interchain sheet. Using cysteine cross-linking, we confirmed that the promyelocytic leukemia zinc finger (PLZF) BTB dimer is strand exchanged in solution, while the FAZF BTB dimer is not. A phylogenic tree of the BTB fold based on both sequence and structural features shows that the common ancestor of the BTB domain in BTB-ZF (bric a brac, tramtrack, broad-complex zinc finger) proteins was a domain-swapped dimer. The differences in the N-termini seen in the FAZF and Miz1 BTB domains appear to be more recent developments in the structural evolution of the domain. Insights into strand exchange in BTB domain dimers from the crystal structures of FAZF and Miz1.,Stogios PJ, Cuesta-Seijo JA, Chen L, Pomroy NC, Prive GG J Mol Biol. 2010 Jul 30;400(5):983-97. Epub 2010 May 21. PMID:20493880[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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