First Author | Spronk CA | Year | 2000 |
Journal | Nat Struct Biol | Volume | 7 |
Issue | 12 | Pages | 1100-4 |
PubMed ID | 11101889 | Mgi Jnum | J:66140 |
Mgi Id | MGI:1928024 | Doi | 10.1038/81944 |
Citation | Spronk CA, et al. (2000) The Mad1-Sin3B interaction involves a novel helical fold. Nat Struct Biol 7(12):1100-4 |
abstractText | Sin3A or Sin3B are components of a corepressor complex that mediates repression by transcription factors such as the helix-loop-helix proteins Mad and Mxi. Members of the Mad/Mxi family of repressors play important roles in the transition between proliferation and differentiation by down-regulating the expression of genes that are activated by the proto-oncogene product Myc. Here, we report the solution structure of the second paired amphipathic helix (PAH) domain (PAH2) of Sin3B in complex with a peptide comprising the N-terminal region of Mad1. This complex exhibits a novel interaction fold for which we propose the name 'wedged helical bundle'. Four alpha-helices of PAH2 form a hydrophobic cleft that accommodates an amphipathic Mad1 alpha-helix. Our data further show that, upon binding Mad1, secondary structure elements of PAH2 are stabilized. The PAH2-Mad1 structure provides the basis for determining the principles of protein interaction and selectivity involving PAH domains. |