Polar, uncharged, hydrophilic amino acid. Similar in structure to serine, but with an additional methyl group attached on the side chain. Also a frequent phosphorylation target by protein kinases.

Formula: C₄H₉NO₃
Molecular Weight: 119.12
Three-letter code: Thr
One-letter code: T

Threonine is one of the amino acids which our bodies do not create; it must be ingested. It is important for the formation of tooth enamel, collagen, and elastrin. It metabolizes fat and prevents the buildup of fat in the liver. It is useful with intestinal disorders, and indigestion, including preventing ulcers.

Foods containing threonine include:

• meat
• seafood
• dairy products
• eggs
• beans
• brown rice
• legumes
• nuts and seeds
• whole grains

structural formula for threonine:

    H   H    O        H
     \ /      \\     /
 H -- C        C -- O
       \      /
   H -- C -- C         threonine
       /    / \        C4H9NO3
      O    H   N
      |       / \
      H      H   H