Structure of the Acidobacteria homodimeric reaction center bound with cytochrome c.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36517472.
- Also identified by DOI 10.1038/s41467-022-35460-6 and PMC identifier 9751088.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Photosynthesis converts light energy to chemical energy to fuel life on earth. Light energy is harvested by antenna pigments and transferred to reaction centers (RCs) to drive the electron transfer (ET) reactions. Here, we present cryo-electron microscopy (cryo-EM) structures of two forms of the RC from the microaerophilic Chloracidobacterium thermophilum (CabRC): one containing 10 subunits, including two different cytochromes; and the other possessing two additional subunits, PscB and PscZ. The larger form contained 2 Zn-bacteriochlorophylls, 16 bacteriochlorophylls, 10 chlorophylls, 2 lycopenes, 2 hemes, 3 Fe<sub>4</sub>S<sub>4</sub> clusters, 12 lipids, 2 Ca<sup>2+</sup> ions and 6 water molecules, revealing a type I RC with an ET chain involving two hemes and a hybrid antenna containing bacteriochlorophylls and chlorophylls. Our results provide a structural basis for understanding the excitation energy and ET within the CabRC and offer evolutionary insights into the origin and adaptation of photosynthetic RCs.
Medical subject headings
- Acidobacteria
- Photosynthetic Reaction Center Complex Proteins