Abstract
Protein photosensors are versatile tools for studying ligand-regulated allostery and signaling. Fundamental to these processes is the amount of energy that can be provided by a photosensor to control downstream signaling events. Such regulation is exemplified by the phototropins - plant serine/threonine kinases that are activated by blue light via conserved LOV (light, oxygen and voltage) domains. The core photosensor of oat phototropin 1 is a LOV domain that interacts in a light-dependent fashion with an adjacent α-helix (Jα) to control kinase activity. We used solution NMR measurements to quantify the free energy of the LOV domain-Jα-helix binding equilibrium in the dark and lit states. These data indicate that light shifts this equilibrium by ∼3.8 kcal mol-1, thus quantifying the energy available through LOV-Jα for light-driven allosteric regulation. This study provides insight into the energetics of light sensing by phototropins and benchmark values for engineering photoswitchable systems based on the LOV-Jα interaction.
Original language | English (US) |
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Pages (from-to) | 491-497 |
Number of pages | 7 |
Journal | Nature chemical biology |
Volume | 4 |
Issue number | 8 |
DOIs | |
State | Published - Aug 2008 |
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology