Species differences in unlocking B-side electron transfer in bacterial reaction centers.
The structure of the bacterial photosynthetic reaction center (RC) reveals symmetry-related electron transfer (ET) pathways, but only one path is used in native RCs. Analogous mutations have been made in two Rhodobacter (R.) species. A glutamic acid at position 133 in the M subunit increases transmembrane charge separation via the naturally inactive (B-side) path through impacts on primary ET in mutant R. sphaeroidesRCs. Prior work showed that the analogous substitution in the R. capsulatusRC also increases B-side activity, but mainly affects secondary ET. The overall yields of transmembrane ET are similar, but enabled in fundamentally different ways.
Biosciences Division, Argonne National Laboratory, Lemont, IL, USA.
Nicholas P
NP
Dylla
Department of Chemistry, Washington University, St. Louis, MO, USA.
Kaitlyn M
KM
Faries
Biosciences Division, Argonne National Laboratory, Lemont, IL, USA.
Ryan M
RM
Wyllie
Biosciences Division, Argonne National Laboratory, Lemont, IL, USA.
Angela M
AM
Swenson
Biosciences Division, Argonne National Laboratory, Lemont, IL, USA.
Deborah K
DK
Hanson
Department of Chemistry, Washington University, St. Louis, MO, USA.
Dewey
D
Holten
Department of Chemistry, Washington University, St. Louis, MO, USA.
Christine
C
Kirmaier
Biosciences Division, Argonne National Laboratory, Lemont, IL, USA.
Philip D
PD
Laible
D019943:Amino Acid Substitution; D004579:Electron Transport / Q000235:genetics*; D007700:Kinetics; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D010788:Photosynthesis / Q000235:genetics*; D016354:Rhodobacter capsulatus / Q000235:genetics* / Q000254:growth & development; D012242:Rhodobacter sphaeroides / Q000235:genetics* / Q000254:growth & development
charge separation; high-throughput mutagenesis; photosynthetic bacteria; rapid screening; time-resolved spectroscopy