Structure of a symmetric photosynthetic reaction center-photosystem.
Science
; 357(6355): 1021-1025, 2017 09 08.
Article
in En
| MEDLINE
| ID: mdl-28751471
ABSTRACT
Reaction centers are pigment-protein complexes that drive photosynthesis by converting light into chemical energy. It is believed that they arose once from a homodimeric protein. The symmetry of a homodimer is broken in heterodimeric reaction-center structures, such as those reported previously. The 2.2-angstrom resolution x-ray structure of the homodimeric reaction center-photosystem from the phototroph Heliobacterium modesticaldum exhibits perfect C2 symmetry. The core polypeptide dimer and two small subunits coordinate 54 bacteriochlorophylls and 2 carotenoids that capture and transfer energy to the electron transfer chain at the center, which performs charge separation and consists of 6 (bacterio)chlorophylls and an iron-sulfur cluster; unlike other reaction centers, it lacks a bound quinone. This structure preserves characteristics of the ancestral reaction center, providing insight into the evolution of photosynthesis.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Bacterial Proteins
/
Photosynthetic Reaction Center Complex Proteins
/
Clostridiales
Language:
En
Journal:
Science
Year:
2017
Document type:
Article
Affiliation country: