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

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 thatmore » modified LH2 complexes, combined with engineered (B)Chl biosynthesis pathways in vivo, have potential for retaining high efficiency whilst acquiring increased spectral range.« less

Authors:
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Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Photosynthetic Antenna Research Center (PARC); Pennsylvania State Univ., University Park, PA (United States); Washington Univ., St. Louis, MO (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & Biosciences Division; Biotechnology and Biological Sciences Research Council (BBSRC); National Science Foundation (NSF); European Commission Marie Skłodowska-Curie Global Fellowship
OSTI Identifier:
1482755
Alternate Identifier(s):
OSTI ID: 1566431
Grant/Contract Number:  
SC0001035; FG02-94ER20137; BB/M000265/1
Resource Type:
Journal Article: Published Article
Journal Name:
Biochimica et Biophysica Acta - Bioenergetics
Additional Journal Information:
Journal Name: Biochimica et Biophysica Acta - Bioenergetics Journal Volume: 1860 Journal Issue: 3; Journal ID: ISSN 0005-2728
Publisher:
Elsevier
Country of Publication:
Netherlands
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; solar (fuels); photosynthesis (natural and artificial); biofuels (including algae and biomass); bio-inspired; charge transport; membrane; synthesis (novel materials); synthesis (self-assembly); Rhodobacter sphaeroides; LH2; bacteriochlorophyll; chlorophyll; light harvesting; ligand binding; protein engineering

Citation Formats

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. Engineering of B800 bacteriochlorophyll binding site specificity in the Rhodobacter sphaeroides LH2 antenna. Netherlands: N. p., 2018. Web. doi:10.1016/j.bbabio.2018.11.008.
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, & Hunter, C. Neil. Engineering of B800 bacteriochlorophyll binding site specificity in the Rhodobacter sphaeroides LH2 antenna. Netherlands. https://doi.org/10.1016/j.bbabio.2018.11.008
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. Fri . "Engineering of B800 bacteriochlorophyll binding site specificity in the Rhodobacter sphaeroides LH2 antenna". Netherlands. https://doi.org/10.1016/j.bbabio.2018.11.008.
@article{osti_1482755,
title = {Engineering of B800 bacteriochlorophyll binding site specificity in the Rhodobacter sphaeroides LH2 antenna},
author = {Swainsbury, David J. K. and Faries, Kaitlyn M. and Niedzwiedzki, Dariusz M. and Martin, Elizabeth C. and Flinders, Adam J. and Canniffe, Daniel P. and Shen, Gaozhong and Bryant, Donald A. and Kirmaier, Christine and Holten, Dewey and Hunter, C. Neil},
abstractNote = {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.},
doi = {10.1016/j.bbabio.2018.11.008},
url = {https://www.osti.gov/biblio/1482755}, journal = {Biochimica et Biophysica Acta - Bioenergetics},
issn = {0005-2728},
number = 3,
volume = 1860,
place = {Netherlands},
year = {2018},
month = {11}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at https://doi.org/10.1016/j.bbabio.2018.11.008

Citation Metrics:
Cited by: 9 works
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Works referencing / citing this record:

Carotenoid-to-(bacterio)chlorophyll energy transfer in LH2 antenna complexes from Rba. sphaeroides reconstituted with non-native (bacterio)chlorophylls
journal, July 2019


Sequential energy transfer driven by monoexponential dynamics in a biohybrid light-harvesting complex 2 (LH2)
journal, October 2019