PXD012206

PXD012206 is an original dataset announced via ProteomeXchange.

Title	Structure of NDH the complex I-like molecule of oxygenic photosynthesis
Description	Cyclic electron flow (CEF) around photosystem I (PSI) is a mechanism by which photosynthetic organisms balance levels of ATP and NADPH necessary for efficient photosynthesis1,2. The NAD(P)H dehydrogenase-like complex (NDH) is a key component of this pathway in most oxygenic photosynthetic organisms3,4 and the last large photosynthetic membrane protein complex of unknown structure. Related to the respiratory NADH dehydrogenase complex (complex I), NDH transfers electrons originating from PSI to the plastoquinone (PQ) pool, while pumping protons across the thylakoid membrane, thereby increasing the amount of ATP produced per NADP+ molecule reduced4,5. NDH possesses 11 of the 14 core complex I subunits as well as several oxygenic photosynthesis specific (OPS) subunits, which are conserved from cyanobacteria to higher plants3,6. However, the three complex I core subunits involved in accepting electrons from NAD(P)H are notably absent in NDH3,5,6. Thus, how NDH acquires and transfers electrons to PQ is presently unclear. Nevertheless, the OPS subunits, specifically NdhS, are proposed to enable NDH to accept electrons from ferredoxin (Fd), its electron donor3–5,7. Here we report a 3.1 Å structure of the ~0.42 MDa NDH complex from the thermophilic cyanobacterium Thermosynechoccous elongatus BP-1 (T. elongatus) obtained by single-particle cryo-electron microscopy (cryo-EM). Our maps reveal the structure and arrangement of the principle OPS subunits in the NDH complex, as well as an unexpected cofactor near the PQ-binding site in the peripheral arm. The location of the OPS subunits supports a role in electron transfer and defines two potential Fd-binding sites at the apex of the peripheral arm. Together, these results suggest multiple electron transfer routes could be present in NDH, which would serve to maximize PQ reduction and avoid deleterious off-target chemistry of the semi-plastoquinone radical.
HostingRepository	PRIDE
AnnounceDate	2019-02-18
AnnouncementXML	Submission_2019-02-18_03:53:14.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Andrew Bayne
SpeciesList	scientific name: Thermosynechococcus elongatus BP-1; NCBI TaxID: 197221;
ModificationList	iodoacetamide derivatized residue
Instrument	impact II

Revision	Datetime	Status	ChangeLog Entry
0	2019-01-02 00:21:14	ID requested
⏵ 1	2019-02-18 03:53:15	announced

Laughlin TG, Bayne AN, Trempe JF, Savage DF, Davies KM, oxygenic photosynthesis. Nature, 566(7744):411-414(2019) [pubmed]

curator keyword: Biological

submitter keyword: NAD(P)H dehydrogenase-like complex, photosynthesis, cyclic electron flow, bioenergetics, membrane protein structure, electron cryo-microscopy

Jean-Francois Trempe
contact affiliation	McGill University
contact email	jeanfrancois.trempe@mcgill.ca
lab head
Andrew Bayne
contact affiliation	McGill University
contact email	andrew.bayne@mail.mcgill.ca
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD012206
     1. Label: PRIDE project
     2. Name: Structure of NDH the complex I-like molecule of oxygenic photosynthesis