Leucine

Aliphatic amino acid. Uncharged, nonpolar, hydrophobic. Has the same chemical formula as isoleucine, but with one of the methyl groups moved to another carbon. Commonly used in DNA binding proteins to dimerize two alpha-helices (see: leucine zipper).

Formula: C₆H₁₃NO₂
Molecular Weight: 131.17
Three-letter code: Leu
One-letter code: L

Leucine has the following structure:

    COOH
    |
H2N-C-H
    |
    CH2
    |
    CH
   /  \
  CH3  CH3