Allothreonine
Allothreonine is an amino acid with the formula. It is the diastereomer of the amino acid threonine. Like most other amino acids, allothreonine is a water-soluble colorless solid. Although not one of the proteinogenic amino acids, it has often been the subject for the synthesis of novel proteins using an expanded genetic code. Racemic allothreonine can be produced in the laboratory from bromomethoxybutyric acid.
Structure
Threonine has R, S stereochemistry at carbons 2 and 3 for the naturally occurring stereoisomer and S, R stereochemistry for its enantiomer. Allothreonine has S, S stereochemistry at carbons 2 and 3 in the natural stereoisomer, but R, R in the very rare enantiomer.| |
| L-Threonine and D-Threonine |
| |
| L-Allothreonine and D-Allothreonine |
Occurrence
Katanosins are a group of potent antibiotics contain allothreonine.Peptides containing the allothreonine residue have also been isolated from natural source.