They are phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine. Like valine and isoleucine, leucine is a branched-chain amino acid. The amino acids in question are leucine, isoleucine and valine. This operon is bound and inactivated by valine, leucine, and isoleucine. Among the proteinogenic amino acids, there are three BCAAs&colon; leucine, isoleucine, and valine. The complex is essential for breaking down the amino acids leucine, isoleucine, and valine. This changes codon 6 from encoding the amino acid glutamic acid to encoding valine . Mesenteroides also require glutamic acid and valine. Consequently, residues such as alanine, glycine and valine tend to be preferred. Radiolabeling studies identified phenylalanine and valine as the precursors to capsaicin. These bacteria synthesize pantothenate from the amino acid aspartate and a metabolite in valine biosynthesis. The V617F mutation is a change of valine to phenylalanine at the 617 position. Secretin also has an amidated carboxyl-terminal amino acid which is valine. The compound is an isomer of the more common amino acid valine. Examples include prolinol (from proline) and valinol (from valine).