Role of tyrosine M210 in the initial charge separation of reaction centers of Rhodobacter sphaeroides
Femtosecond spectroscopy was used in combination with site-directed mutagenesis to study the\ninfluence of tyrosine M210 (YM210) on the primary electron transfer in the reaction center of Rhodobacter\nsphaeroides. The exchange of YM210 to phenylalanine caused the time constant of primary electron transfer\nto increase from 3.5 f 0.4 ps to 16 f 6 ps while the exchange to leucine increased the time constant even\nmore to 22 f 8 ps. The results suggest that tyrosine M210 is important for the fast rate of the primary\nelectron transfer.