2ERG: Crystal Structure Of Leu3 Dna-Binding Domain With A Single H50c Mutation Complexed With A 15mer Dna Duplex

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.
PDB ID: 2ERGDownload
MMDB ID: 53074
PDB Deposition Date: 2005/10/24
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 3.15  Å
Source Organism:
synthetic construct
Similar Structures:
Biological Unit for 2ERG: tetrameric; determined by author
Molecular Components in 2ERG
Label Count Molecule
Proteins (2 molecules)
Regulatory Protein Leu3(Gene symbol: LEU3)
Molecule annotation
Nucleotide(1 molecule)
5'- D(*tp*tp*gp*cp*cp*gp*gp*tp*ap*cp*cp*gp*gp*cp*a)-3'
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB