Green fluorescent protein (GFP), originally isolated from the jellyfish Aequorea victoria (PDB
entry 1ema), fluorsceses green (509nm) when exposed to blue light (395nm and 475nm). It is
one of the most important proteins used in biological research because it can be used to tag
otherwise invisible gene products of interest and thus observe their existence, location and
movement.
Exploring the Structure
GFP is a beta barrel protein with 11 beta sheets. It is a 26.9kDa protein made up of 238 amino
acids. The , responsible for the fluorescent properties of the protein, is buried
inside the beta barrel as part of the central alpha helix passing through the barrel. The
chromophore forms via spontaneous cyclization and oxidation of three residues in the central
alpha helix: -Thr65 (or Ser65)-Tyr66-Gly67. This cyclization and oxidation creates the
chromophore's five-membered ring via a new bond between the threonine and the glycine
residues.[1]
