SNAP output for PDB entry 1if1 [SNAP web server]

PDB-id

1if1; SNAP-derived features in text and JSON formats; DNAproDB

Class

transcription-DNA

Method

X-ray (3.0 Å)

Summary

Interferon regulatory factor 1 (irf-1) complex with DNA

Reference

Escalante CR, Yie J, Thanos D, Aggarwal AK (1998): "Structure of IRF-1 with bound DNA reveals determinants of interferon regulation." Nature, 391, 103-106. doi: 10.1038/34224.

Abstract

The family of interferon regulatory factor (IRF) transcription factors is important in the regulation of interferons in response to infection by virus and in the regulation of interferon-inducible genes. The IRF family is characterized by a unique 'tryptophan cluster' DNA-binding region. Here we report the crystal structure of the IRF-1 region bound to the natural positive regulatory domain I (PRD I) DNA element from the interferon-beta promoter. The structure provides the first three-dimensional view of a member of the growing IRF family, revealing a new helix-turn-helix motif that latches onto DNA through three of the five conserved tryptophans. The motif selects a short GAAA core sequence through an obliquely angled recognition helix, with an accompanying bending of the DNA axis in the direction of the protein. Together, these features suggest a basis for the occurrence of GAAA repeats within IRF response elements and provide clues to the assembly of the higher-order interferon-beta enhancesome.