L-cysteine (C)

Side chain polarity Reset
Display the thio alcohol (thiol) group as Ball & Stick.
Cys differs structurally from Ser only in the sulfur for oxygen substitution. Cys is found in the apolar interior of proteins more often than Ser; it also forms covalent disulfide bonds with other Cys residues to help stabilize the tertiary folding of extracellular proteins.

Some facts on L-cysteine.

  1. Abbreviation: Cys.
  2. One-letter code: C.
  3. Molecular mass: 121 daltons.
  4. Side chain (or R-group) features:
Return to image of Cys.