SNAP output for PDB entry 2er8 [SNAP web server]

PDB-id

2er8; SNAP-derived features in text and JSON formats; DNAproDB

Class

transcription activator-DNA

Method

X-ray (2.85 Å)

Summary

Crystal structure of leu3 DNA-binding domain complexed with a 12mer DNA duplex

Reference

Fitzgerald MX, Rojas JR, Kim JM, Kohlhaw GB, Marmorstein R (2006): "Structure of a Leu3-DNA complex: recognition of everted CGG half-sites by a Zn2Cys6 binuclear cluster protein." Structure, 14, 725-735. doi: 10.1016/j.str.2005.11.025.

Abstract

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.