Novel fold and wing structure of Forkhead transcription factor facilitate DNA binding.

ABSTRACT: Forkhead homologue 1 (Fkh1) is a yeast transcription factor that plays essential roles in cell-cycle dynamics. Here, we report the co-crystal structure of the DNA-binding domain (DBD) of the yeast Fkh1 protein in complex with a 19-base pair oligonucleotide containing the core binding site and flanking regions. The three-dimensional structure of the Fkh1-DBD reveals a previously unknown protein fold among all known Forkhead proteins. The winged-helix fold forms base-specific contacts of α-helix H3 with the major groove of the core binding site. Wing 1 and Wing 2 form DNA shape-mediated contacts with the minor groove of the binding site flanking regions. The conformation of Wing 2 is distinct from all known Forkhead proteins, with α-helices H5 and H6 wrapping back onto the protein core, crea

SUBMITTER: Wang GL 

PROVIDER: S-EPMC12458081 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature