Tandem binding in crystals of a trp repressor/operator half-site complex

Nature. 1993 Nov 11;366(6451):178-82. doi: 10.1038/366178a0.

Abstract

The crystal structure of trp repressor tandemly bound in a 2:1 complex to a 16-base-pair palindromic DNA containing a central trp operator half-site has been determined and refined to 2.4 A resolution. Despite dramatically different DNA sequence contexts and crystallization conditions, the protein/DNA interface is essentially identical to that seen in the original trp repressor/operator complex structure. Water-mediated sequence recognition by trp repressor is likely to be related to the unusual end-on approach of the recognition helix (E), which allows sharing of the major groove by tandem dimers. The tandem complex model accounts for the mutational sensitivity of all trp operator base pairs. The structure also provides the first detailed view of the tandem interaction, revealing a key role for the amino-terminal arms.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bacterial Proteins*
  • Base Sequence
  • Computer Graphics
  • Crystallography, X-Ray
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / metabolism
  • Escherichia coli / genetics
  • Models, Molecular
  • Molecular Sequence Data
  • Operator Regions, Genetic*
  • Protein Binding
  • Repressor Proteins / chemistry
  • Repressor Proteins / metabolism*

Substances

  • Bacterial Proteins
  • DNA, Bacterial
  • Repressor Proteins
  • TRPR protein, E coli