Abstract
Proton pathways in green fluorescent protein (GFP) are more extended than previously reported. In the x-ray data of wild-type GFP, a two-step exit pathway exists from the active site to the protein surface, controlled by a threonine switch. A proton entry pathway begins at a glutamate-lysine cluster around Glu-5, and extends all the way to the buried Glu-222 near the active site. This structural evidence suggests that GFP may function as a portable light-driven proton-pump, with proton emitted in the excited state through the switchable exit pathway, and replenished from Glu-222 and the Glu-5 entry pathway in the ground state.
Original language | English |
---|---|
Pages (from-to) | 2452-2461 |
Number of pages | 10 |
Journal | Biophysical Journal |
Volume | 88 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2005 |