Publication Abstract from PubMed
Gal4 is the prototypical Zn2Cys6 binuclear cluster transcriptional regulator that binds as a homodimer to DNA containing inverted CGG half-sites. Leu3, a member of this protein family, binds to everted (opposite polarity to inverted) CGG half-sites, and an H50C mutation within the Leu3 Zn2Cys6 binuclear motif abolishes its transcriptional repression function without impairing DNA binding. We report the X-ray crystal structures of DNA complexes with Leu3 and Leu3(H50C) and solution DNA binding studies of selected Leu3 mutant proteins. These studies reveal the molecular details of everted CGG half-site recognition, and suggest a role for the H50C mutation in transcriptional repression. Comparison with the Gal4-DNA complex shows an unexpected conservation in the DNA recognition mode of inverted and everted CGG half-sites, and points to a critical function of a linker region between the Zn2Cys6 binuclear cluster and dimerization regions in DNA binding specificity. Broader implications of these findings are discussed.
Structure of a Leu3-DNA complex: recognition of everted CGG half-sites by a Zn2Cys6 binuclear cluster protein.,Fitzgerald MX, Rojas JR, Kim JM, Kohlhaw GB, Marmorstein R Structure. 2006 Apr;14(4):725-35. PMID:16615914[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
