Three-dimensional structure of thymidine phosphorylase from Escherichia coli at 2.8 Å resolution

Academic Article

Abstract

  • The three-dimensional structure of thymidine phosphorylase from Escherichia coli has been determined at 2.8 Å resolution using multiple-isomorphous-replacement techniques. The amino acid sequence deduced from the deoA DNA sequence is also reported. Thymidine phosphorylase exists in the crystal as an S-shaped dimer in which the subunits are related by a crystallographic 2-fold axis. Each subunit is composed of a small α-helical domain of six helices and a large α/β domain. The α/β domain includes a six-stranded mixed β-sheet and a four-stranded antiparallel β-sheet. The active site has been identified by difference Fourier analyses of the binding of thymine and thymidine and lies in a cavity between the small and large domains. The central β-sheet is splayed open to accommodate a putative phosphate-binding site which is probably occupied by a sulfate ion in the crystal.
  • Published In

    Author List

  • Walter MR; Cook WJ; Cole LB; Short SA; Koszalka GW; Krenitsky TA; Ealick SE
  • Start Page

  • 14016
  • End Page

  • 14022
  • Volume

  • 265
  • Issue

  • 23