Light-driven electron transfer (ET) in bacterial photosynthetic reaction centers proceeds in a transmembrane protein complex with two symmetric pathways of cofactors – the A pathway operational, while the B pathway is effectively inoperative – leaving efficient activation of the B pathway a challenge. Here, the authors redesign the non-functional B branch in the Cereibacter sphaeroides photosynthetic reaction center, enhancing long-range ET by incorporating tryptophan residues at strategic positions between cofactors, achieving variants with impressive transmembrane charge separation yields due to the increased competency of secondary ET (up to 95%).
- Deborah K. Hanson
- James C. Buhrmaster
- Philip D. Laible
