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

are a group of potent antibiotics contain allothreonine.
Peptides containing the allothreonine residue have also been isolated from natural source.