Structure restraints from heteronuclear pseudocontact shifts generated by lanthanide tags at two different sites

Benjamin J.G. Pearce, Shereen Jabar, Choy-Theng Loh, Monika Szabo, Bim Graham, Gottfried Otting

Research output: Contribution to journalArticleResearchpeer-review

4 Citations (Scopus)

Abstract

Pseudocontact shifts (PCS) encode long-range information on 3D structures of protein backbones and side-chains. The level of structural detail that can be obtained increases with the number of different sites tagged with a paramagnetic metal ion to generate PCSs. Here we show that PCSs from two different sites can suffice to determine the structure of polypeptide chains and their location and orientation relative to the magnetic susceptibility tensor χ, provided that PCSs are available for 1H as well as heteronuclear spins. In addition, PCSs from two different sites are shown to provide detailed structural information on the conformation of methyl group-bearing amino-acid side-chains. A previously published ensemble structure of ubiquitin is shown to explain the magnetic susceptibility and alignment tensors slightly better than structures that try to explain the experimental data by a single conformation, illustrating the potential of PCSs as a tool to investigate small conformational changes.

Original languageEnglish
Pages (from-to)19-32
Number of pages14
JournalJournal of Biomolecular NMR
Volume68
Issue number1
DOIs
Publication statusPublished - 1 May 2017

Keywords

  • Human ubiquitin
  • Lanthanide tag
  • Pseudocontact shift
  • Residual anisotropic chemical shifts
  • Structure determination

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