Real-time tracking of phytochrome's ring D orientational changes during Pr photoisomerization: Two Pr isoforms with different photoisomerization yields

Phytochromes' ring D orientational changes are tracked during Z-to-E photoisomerization by polarization resolved femtosecond visible pump-infrared probe spectroscopy. Two distinct Pr isoforms Pr-I and Pr-II exhibit photoisomerization yields of 3% and 29%, respectively.