L-threonine CAS NO.72-19-5

threonine is an amino acid that is used in the biosynthesis of proteins. it contains an α-amino group (which is in the protonated −nh+
3 form under biological conditions), a carboxyl group (which is in the deprotonated −coo⁻ form under biological conditions), and a side chain containing a hydroxyl group, making it a polar, uncharged amino acid. it is essential in humans, meaning the body cannot synthesize it: it must be obtained from the diet. threonine is synthesized from aspartate in bacteria such as e. coli.^[3] it is encoded by all the codons starting ac (act, acc, aca, and acg).

threonine sidechains are often hydrogen bonded; the most common small motifs formed are based on interactions with serine: st turns, st motifs (often at the beginning of alpha helices) and st staples (usually at the middle of alpha helices).