A retraction was published this week in Structure in relation to a crystal structure of a complex of a G protein-coupled receptor and a G protein:
In this paper, a cocrystal structure was described of the G-protein heterodimer Gb1g2 bound to a C-terminal peptide from the parathyroid hormone receptor-1 (PTH1R) at 3.0A ° resolution (PDB id 2QNS). A subsequent refinement was later deposited in the Protein Data Bank (PDB id 3KJ5). While this structure represents a new crystal form of the Gb1g2 heterodimer, because of the lack of clear and continuous electron density for the receptor peptide in the complex structure, the paper is being retracted. We apologize for any confusion this may have caused.
What does “lack of clear and continuous electron density” mean? And why is this only coming to light now? Was this an honest mistake, or faking data?