Nonpolar

Valine Amino Acid Code (Val, V)

Valine amino acid uses V as its one-letter code and Val as its three-letter code. It is encoded by GUU, GUC, GUA, GUG.

One-letter
V
Three-letter
Val
Codons
GUUGUCGUAGUG

Valine Code and Properties

Full name
Valine
One-letter code
V
Three-letter code
Val
Molecular weight
117.15 Da
Essential amino acid
Yes
Charged side chain
No

Codons for Valine

These RNA codons use U. The equivalent DNA codons use T in the same positions.

What to Remember

  • V is the one-letter protein code for Valine.
  • Val is the three-letter code used in many tables, structures, and mutation notes.
  • GUU, GUC, GUA, GUG are RNA codons. Coding DNA uses T where RNA uses U.
  • Branched-chain, hydrophobic amino acid. This page uses the standard genetic code.

Need More Context?

How to read Valine in a sequence

Protein sequences usually use one-letter codes because they are compact. In that notation, Vmeans Valine. The three-letter code Val is easier to read in structure notes, mutation descriptions, and teaching materials.

Codons are different from amino acid letter codes. A codon is a three-base RNA word read during translation, while an amino acid code is the protein shorthand. The codons GUU, GUC, GUA, GUG all point to Valinein the standard genetic code.

What the property label means

The Valine amino acid is classified here as nonpolar. That label is a shortcut for first-pass interpretation, not a complete description of every chemical behavior.

Valine is often checked because hydrophobic residues tend to be important in protein cores, membranes, and folded structural regions. The exact effect depends on protein context, neighboring residues, pH, solvent exposure, and the folded state of the whole protein.

Residue vs free amino acid

In a protein sequence, Valine is usually discussed as an amino acid residue. That means the amino acid has been incorporated into a peptide chain and has lost the atoms removed during peptide bond formation. The one-letter code V and three-letter code Val refer to that residue in sequence notation.

The listed molecular weight is for the free amino acid. Protein mass calculations often use residue masses instead, because water is removed when peptide bonds form.

Common mistakes

Do not confuse the one-letter code V with a DNA or RNA base. It is an amino acid symbol, not a nucleotide in a codon.

Do not read codons without checking the frame. A triplet that encodes Valine in one frame may disappear in another frame. For gene design, check organism-specific codon usage after confirming the basic amino acid identity.

Common Questions

What is the one-letter code for Valine?

The one-letter amino acid code for Valine is V.

What is the three-letter code for Valine?

The three-letter amino acid code for Valine is Val.

Which codons encode Valine?

Valine is encoded by GUU, GUC, GUA, GUG in the standard genetic code.