The structure of PurR mutant L54M shows an alternative route to DNA kinking.


Journal Article

The crystal structure of the purine repressor mutant L54M bound to hypoxanthine and to the purF operator provides a stereochemical understanding of the high DNA affinity of this hinge helix mutant. Comparison of the PurR L54M-DNA complex to that of the wild type PurR-DNA complex reveals that these purine repressors bind and kink DNA similarly despite significant differences in their minor groove contacts and routes to interdigitation of the central C.G:G.C base pair step. Modeling studies, supported by genetic and biochemical data, show that the stereochemistry of the backbone atoms of the abutting hinge helices combined with the rigidity of the kinked base pair step constrain the interdigitating residue to leucine or methionine for the LacI/GalR family of transcription regulators.

Full Text

Duke Authors

Cited Authors

  • Arvidson, DN; Lu, F; Faber, C; Zalkin, H; Brennan, RG

Published Date

  • June 1998

Published In

Volume / Issue

  • 5 / 6

Start / End Page

  • 436 - 441

PubMed ID

  • 9628480

Pubmed Central ID

  • 9628480

International Standard Serial Number (ISSN)

  • 1072-8368

Digital Object Identifier (DOI)

  • 10.1038/nsb0698-436


  • eng

Conference Location

  • United States