Unknown amino acids and nucleic residues
From Proteopedia
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* N: 123 entries. | * N: 123 entries. | ||
| - | While one might expect unknown residues to be more common in entries released in the 20th century, in fact, they are far more common since the success of [[ | + | While one might expect unknown residues to be more common in entries released in the 20th century, in fact, they are far more common since the 21st century success of [[Electron cryomicroscopy]]. Cryo-EM is often used on samples with unknown components, and has a lower median resolution than does [[X-ray crystallography]]. |
Revision as of 15:59, 24 March 2025
Atomic coordinate file data entries in the Protein Data Bank may include atoms of unknown amino acids, designated "UNK", or nucleic residues, designated "N". Total such entries in March, 2025 are:
- UNK: 1,767 entries.
- N: 123 entries.
While one might expect unknown residues to be more common in entries released in the 20th century, in fact, they are far more common since the 21st century success of Electron cryomicroscopy. Cryo-EM is often used on samples with unknown components, and has a lower median resolution than does X-ray crystallography.
