Engineering of B800 bacteriochlorophyll binding site specificity in the Rhodobacter sphaeroides LH2 antenna

Swainsbury, David J.K., Faries, Kaitlyn M., Niedzwiedzki, Dariusz M., Martin, Elizabeth C., Flinders, Adam J., Canniffe, Daniel P., Shen, Gaozhong, Bryant, Donald A., Kirmaier, Christine, Holten, Dewey and Hunter, C. Neil (2019) Engineering of B800 bacteriochlorophyll binding site specificity in the Rhodobacter sphaeroides LH2 antenna. Biochimica et Biophysica Acta - Bioenergetics, 1860 (3). pp. 209-223. ISSN 0005-2728

Full text not available from this repository. (Request a copy)

Abstract

The light-harvesting 2 complex (LH2) of the purple phototrophic bacterium Rhodobacter sphaeroides is a highly efficient, light-harvesting antenna that allows growth under a wide-range of light intensities. In order to expand the spectral range of this antenna complex, we first used a series of competition assays to measure the capacity of the non-native pigments 3-acetyl chlorophyll (Chl) a, Chl d, Chl f or bacteriochlorophyll (BChl) b to replace native BChl a in the B800 binding site of LH2. We then adjusted the B800 site and systematically assessed the binding of non-native pigments. We find that Arg −10 of the LH2 β polypeptide plays a crucial role in binding specificity, by providing a hydrogen-bond to the 3-acetyl group of native and non-native pigments. Reconstituted LH2 complexes harbouring the series of (B)Chls were examined by transient absorption and steady-state fluorescence spectroscopies. Although slowed 10-fold to ~6 ps, energy transfer from Chl a to B850 BChl a remained highly efficient. We measured faster energy-transfer time constants for Chl d (3.5 ps) and Chl f (2.7 ps), which have red-shifted absorption maxima compared to Chl a. BChl b, red-shifted from the native BChl a, gave extremely rapid (≤0.1 ps) transfer. These results show that modified LH2 complexes, combined with engineered (B)Chl biosynthesis pathways in vivo, have potential for retaining high efficiency whilst acquiring increased spectral range.

Item Type: Article
Additional Information: Funding Information: DJKS, ECM, AJF and CNH gratefully acknowledge financial support from the Biotechnology and Biological Sciences Research Council (BBSRC UK), award number BB/M000265/1 . KMF, DMN, CK, DAB, GS and DH acknowledge support by the Photosynthetic Antenna Research Center (PARC), an Energy Frontier Research Center funded by the U.S. Department of Energy , Office of Science, and Office of Basic Energy Sciences under Award Number DE-SC 0001035 for the photophysical studies. DAB also acknowledges support from the U. S. National Science Foundation ( MCB-1021725 ) and from the Photosynthetic Systems Program, Division of Chemical Sciences, Geosciences, and Biosciences (CSGB), Office of Basic Energy Sciences of the U.S. Department of Energy ( DE-FG02-94ER20137 ). DPC acknowledges funding from European Commission Marie Skłodowska-Curie Global Fellowship ( 660652 ). Funding Information: DJKS, ECM, AJF and CNH gratefully acknowledge financial support from the Biotechnology and Biological Sciences Research Council (BBSRC UK), award number BB/M000265/1. KMF, DMN, CK, DAB, GS and DH acknowledge support by the Photosynthetic Antenna Research Center (PARC), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences under Award Number DE-SC 0001035 for the photophysical studies. DAB also acknowledges support from the U. S. National Science Foundation (MCB-1021725) and from the Photosynthetic Systems Program, Division of Chemical Sciences, Geosciences, and Biosciences (CSGB), Office of Basic Energy Sciences of the U.S. Department of Energy (DE-FG02-94ER20137). DPC acknowledges funding from European Commission Marie Sk?odowska-Curie Global Fellowship (660652). Funding Information: DJKS, ECM, AJF and CNH gratefully acknowledge financial support from the Biotechnology and Biological Sciences Research Council (BBSRC UK), award number BB/M000265/1. KMF, DMN, CK, DAB, GS and DH acknowledge support by the Photosynthetic Antenna Research Center (PARC), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences under Award Number DE-SC 0001035 for the photophysical studies. DAB also acknowledges support from the U. S. National Science Foundation (MCB-1021725) and from the Photosynthetic Systems Program, Division of Chemical Sciences, Geosciences, and Biosciences (CSGB), Office of Basic Energy Sciences of the U.S. Department of Energy (DE-FG02-94ER20137). DPC acknowledges funding from European Commission Marie Skłodowska-Curie Global Fellowship (660652). Publisher Copyright: © 2018 The Authors
Uncontrolled Keywords: bacteriochlorophyll,chlorophyll,lh2,ligand binding,light harvesting,protein engineering,rhodobacter sphaeroides,biophysics,biochemistry,cell biology ,/dk/atira/pure/subjectarea/asjc/1300/1304
Faculty \ School: Faculty of Science > School of Biological Sciences
Related URLs:
Depositing User: LivePure Connector
Date Deposited: 17 Aug 2022 12:31
Last Modified: 01 Oct 2022 07:41
URI: https://ueaeprints.uea.ac.uk/id/eprint/87359
DOI: 10.1016/j.bbabio.2018.11.008

Actions (login required)

View Item View Item