Ultrafast structural changes within a photosynthetic reaction centre.
Robert DodsPetra BåthDmitry MorozovViktor Ahlberg GagnérDavid ArnlundHoi Ling LukJoachim KübelMichal MajAdams VallejosCecilia WickstrandRobert BosmanKenneth R BeyerleinGarrett NelsonMengning LiangDespina MilathianakiJoseph RobinsonRajiv HarimoorthyPeter BerntsenErik MalmerbergLinda JohanssonRebecka AnderssonSergio CarbajoElin ClaessonChelsie E ConradPeter DahlGreger HammarinMark S HunterChufeng LiStella LisovaAntoine RoyantCecilia SafariAmit SharmaGarth J WilliamsOleksandr YefanovSebastian WestenhoffJan DavidssonDaniel P DePonteSébastien BoutetAnton BartyGergely KatonaGerrit GroenhofGisela BrändénRichard NeutzePublished in: Nature (2020)
Photosynthetic reaction centres harvest the energy content of sunlight by transporting electrons across an energy-transducing biological membrane. Here we use time-resolved serial femtosecond crystallography1 using an X-ray free-electron laser2 to observe light-induced structural changes in the photosynthetic reaction centre of Blastochloris viridis on a timescale of picoseconds. Structural perturbations first occur at the special pair of chlorophyll molecules of the photosynthetic reaction centre that are photo-oxidized by light. Electron transfer to the menaquinone acceptor on the opposite side of the membrane induces a movement of this cofactor together with lower amplitude protein rearrangements. These observations reveal how proteins use conformational dynamics to stabilize the charge-separation steps of electron-transfer reactions.