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E. coli trp repressor forms a domain-swapped array in aqueous alcohol.

ABSTRACT: The E. coli trp repressor (trpR) homodimer recognizes its palindromic DNA binding site through a pair of flexible helix-turn-helix (HTH) motifs displayed on an intertwined helical core. Flexible N-terminal arms mediate association between dimers bound to tandem DNA sites. The 2.5 A X-ray structure of trpR crystallized in 30% (v/v) isopropanol reveals a substantial conformational rearrangement of HTH motifs and N-terminal arms, with the protein appearing in the unusual form of an ordered 3D domain-swapped supramolecular array. Small angle X-ray scattering measurements show that the self-association properties of trpR in solution are fundamentally altered by isopropanol.

SUBMITTER: Lawson CL

PROVIDER: S-EPMC3228604 | biostudies-literature | 2004 Jun

REPOSITORIES: biostudies-literature

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E. coli trp repressor forms a domain-swapped array in aqueous alcohol.

Lawson Catherine L CL Benoff Brian B Berger Tatyana T Berman Helen M HM Carey Jannette J

Structure (London, England : 1993) 20040601 6

The E. coli trp repressor (trpR) homodimer recognizes its palindromic DNA binding site through a pair of flexible helix-turn-helix (HTH) motifs displayed on an intertwined helical core. Flexible N-terminal arms mediate association between dimers bound to tandem DNA sites. The 2.5 A X-ray structure of trpR crystallized in 30% (v/v) isopropanol reveals a substantial conformational rearrangement of HTH motifs and N-terminal arms, with the protein appearing in the unusual form of an ordered 3D domai ...[more]

PMID: 15274929

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