Histidine / HIS / H (EnzDes coloring)

Histidine (HIS or H) is a weakly hydrophilic amino acid. Histidine's pentagonal shape is unique in Foldit. In contrast, phenylalanine has a hexagonal shape, and is hydrophobic.

In the Foldit Lua interface, the functions structure.GetAminoAcid and structure.SetAminoAcid use lowercase "h" for histidine.


Histidine's sidechain can act as both a hydrogen bond donor and acceptor.

Histidine's sidechain contains two nitrogen atoms, one of which which can act as a hydrogen bond acceptor. The other nitrogen atom can act as a hydrogen bond donor. See the Sidechain Bonding Gallery and the Sidechain Bonding Table for other sidechain donors and acceptors.

For more, see Histidine on wikipedia.