Reanalysis of a mu opioid receptor crystal structure reveals a covalent adduct with BU72.
Munro, T.A.(2023) BMC Biol 21: 213-213
- PubMed: 37817141 
- DOI: https://doi.org/10.1186/s12915-023-01689-w
- Primary Citation of Related Structures:  
8E0G - PubMed Abstract: 
The first crystal structure of the active μ opioid receptor (μOR) exhibited several unexplained features. The ligand BU72 exhibited many extreme deviations from ideal geometry, along with unexplained electron density. I previously showed that inverting the benzylic configuration resolved these problems, establishing revised stereochemistry of BU72 and its analog BU74. However, another problem remains unresolved: additional unexplained electron density contacts both BU72 and a histidine residue in the N-terminus, revealing the presence of an as-yet unidentified atom.
Organizational Affiliation: 
School of Life and Environmental Sciences, Deakin University, Burwood, VIC, 3125, Australia. thomas@munro.com.