2ojr
|
Structure of ubiquitin solved by SAD using the Lanthanide-Binding Tag
OverviewOverview
A double-lanthanide-binding tag (dLBT), a small peptide sequence, engineered to bind two lanthanide ions (e.g., Tb3+) with high affinity, was used to solve the phase problem for the structure determination of, ubiquitin by the single-wavelength anomalous diffraction (SAD) method., Since the dLBT is comprised exclusively of encoded amino acids, the, necessity for the incorporation of unnatural amino acids or chemical, modification of the protein as a prerequisite for X-ray structure, determination is eliminated. A construct encoding the dLBT as an, N-terminal fusion with ubiquitin provides for facile expression and, purification using standard methods. Phasing of the single-wavelength, X-ray data (at 2.6 A resolution) using only the anomalous signal from the, two tightly bound Tb3+ ions in the dLBT led to clear electron-density, maps. Nearly 75% of the ubiquitin structure was built using automated, model-building software without user intervention. It is anticipated that, this technique will be broadly applicable, complementing existing, macromolecular phasing methodologies. The dLBT should be particularly, useful in cases where protein derivatization with heavy atoms proves to be, problematic or synchrotron facilities are unavailable.
About this StructureAbout this Structure
2OJR is a Single protein structure of sequence from Homo sapiens with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Double-Lanthanide-Binding Tags for Macromolecular Crystallographic Structure Determination., Silvaggi NR, Martin LJ, Schwalbe H, Imperiali B, Allen KN, J Am Chem Soc. 2007 Jun 6;129(22):7114-7120. Epub 2007 May 12. PMID:17497863
Page seeded by OCA on Wed Jan 23 14:55:24 2008