8C3F

Double mutant I(L177)H/F(M197)H structure of Photosynthetic Reaction Center From Cereibacter sphaeroides strain RV

Summary for 8C3F

• Entry DOI: 10.2210/pdb8c3f/pdb
• Descriptor: Reaction center protein L chain, PHOSPHATE ION, GLYCEROL, ... (19 entities in total)
• Functional Keywords: photosynthetic reaction center, bacteriochlorophyll, rhodobacter sphaeroides, mesophase crystallization, lipid sponge phase, lipid cubic phase, spheroidene, ubiquinone, photosynthesis
• Biological source: Cereibacter sphaeroides 2.4.1; More
• Total number of polymer chains: 3
• Total formula weight: 104119.57

Authors

Gabdulkhakov, A.G.,Selikhanov, G.K.,Fufina, T.Y.,Vasilieva, L.G. (deposition date: 2022-12-23, release date: 2023-03-08, Last modification date: 2024-02-07)

Primary citation

Fufina, T.Y.,Selikhanov, G.K.,Gabdulkhakov, A.G.,Vasilieva, L.G.
Properties and Crystal Structure of the Cereibacter sphaeroides Photosynthetic Reaction Center with Double Amino Acid Substitution I(L177)H + F(M197)H.
Membranes (Basel), 13:-, 2023

PubMed Abstract: The photosynthetic reaction center of the purple bacterium with two site-directed mutations Ile-L177-His and M197 Phe-His is of double interest. The substitution I(L177)H results in strong binding of a bacteriochlorophyll molecule with L-subunit. The second mutation F(M197)H introduces a new H-bond between the C2-acetyl carbonyl group of the bacteriochlorophyll P and His-M197, which is known to enhance the stability of the complex. Due to this H-bond, π -electron system of P finds itself connected to an extensive H-bonding network on the periplasmic surface of the complex. The crystal structure of the double mutant reaction center obtained with 2.6 Å resolution allows clarifying consequences of the Ile L177 - His substitution. The value of the P/P midpoint potential in the double mutant RC was found to be ~20 mV less than the sum of potentials measured in the two RCs with single mutations I(L177)H and F(M197)H. The protein environment of the BChls P and B were found to be similar to that in the RC with single substitution I(L177)H, whereas an altered pattern of the H-bonding networks was found in the vicinity of bacteriochlorophyll P. The data obtained are consistent with our previous assumption on a correlation between the bulk of the H-bonding network connected with the π-electron system of the primary electron donor P and the value of its oxidation potential.

PubMed: 36837660
DOI: 10.3390/membranes13020157

Experimental method

X-RAY DIFFRACTION (2.6 Å)