Sticky triangles: New tools for experimental phasing of biological macromolecules

X-ray crystallography is the prime method for the elucidation of
three-dimensional molecular structures. The determination of novel
structures is hampered by the crystallographic phase problem. For
biological macromolecules experimental phasing is one technique to
solve this phase problem; it usually requires the incorporation of
heavy atoms in the protein crystal.
In this thesis a new class of compounds was developed that combines
heavy atoms for experimental phasing with functional groups for interaction
with biological macromolecules. Three functional groups
interact with protein residues and make the compounds sticky. Three
halogen atoms provide a strong anomalous signal and may be used
for experimental phasing. The halogen atoms form an equilateral
triangle, which is easily recognised in the heavy-atom substructure. So far
several novel protein structures have been solved with the iodine
triangle compound. The sticky compounds of the current work are
readily available and easy to use.