Martin, E.C. orcid.org/0000-0001-9600-7298, Bowie, A.G.M. orcid.org/0009-0008-6246-4544, Wellfare Reid, T. orcid.org/0000-0001-9335-3080 et al. (3 more authors) (2024) Sulfoquinovosyl diacylglycerol is required for dimerisation of the Rhodobacter sphaeroides reaction centre-light harvesting 1 core complex. Biochemical Journal, 481 (13). pp. 823-838. ISSN 0264-6021
Abstract
The reaction centre-light harvesting 1 (RC-LH1) core complex is indispensable for anoxygenic photosynthesis. In the purple bacterium Rhodobacter (Rba.) sphaeroides RC-LH1 is produced both as a monomer, in which 14 LH1 subunits form a C-shaped antenna around 1 RC, and as a dimer, where 28 LH1 subunits form an S-shaped antenna surrounding 2 RCs. Alongside the five RC and LH1 subunits, an additional polypeptide known as PufX provides an interface for dimerisation and also prevents LH1 ring closure, introducing a channel for quinone exchange that is essential for photoheterotrophic growth. Structures of Rba. sphaeroides RC-LH1 complexes revealed several new components; protein-Y, which helps to form the quinone channel; protein-Z, of unknown function and seemingly unique to dimers; and a tightly bound sulfoquinovosyl diacylglycerol (SQDG) lipid that interacts with two PufX arginine residues. This lipid lies at the dimer interface alongside weak density for a second molecule, previously proposed to be an ornithine lipid. In this work we have generated strains of Rba. sphaeroides lacking protein-Y, protein-Z, SQDG or ornithine lipids to assess the roles of these previously unknown components in the assembly and activity of RC-LH1. We show that whilst the removal of either protein-Y, protein-Z or ornithine lipids has only subtle effects, SQDG is essential for the formation of RC-LH1 dimers but its absence has no functional effect on the monomeric complex.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2024 The Author(s). This is an open access article published by Portland Press Limited on behalf of the Biochemical Society and distributed under the Creative Commons Attribution License 4.0 (CC BY - https://creativecommons.org/licenses/by/4.0/). |
Keywords: | Rhodobacter sphaeroides; RC-LH1; light harvesting; lipids; photosynthesis; reaction centre; Rhodobacter sphaeroides; Light-Harvesting Protein Complexes; Bacterial Proteins; Protein Multimerization; Glycolipids; Models, Molecular; Crystallography, X-Ray |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Biosciences (Sheffield) > Department of Molecular Biology and Biotechnology (Sheffield) The University of Sheffield > Faculty of Science (Sheffield) > School of Biosciences (Sheffield) |
Funding Information: | Funder Grant number EUROPEAN COMMISSION - HORIZON 2020 854126 ROYAL SOCIETY URF\R1\191548 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 06 Aug 2024 07:31 |
Last Modified: | 06 Aug 2024 07:31 |
Status: | Published |
Publisher: | Portland Press Ltd. |
Refereed: | Yes |
Identification Number: | 10.1042/bcj20240125 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:215457 |