Structural basis for electron transport mechanism of complex I-like photosynthetic NAD(P)H dehydrogenase

Nat Commun. 2020 Jan 30;11(1):610. doi: 10.1038/s41467-020-14456-0.

Abstract

NAD(P)H dehydrogenase-like (NDH) complex NDH-1L of cyanobacteria plays a crucial role in cyclic electron flow (CEF) around photosystem I and respiration processes. NDH-1L couples the electron transport from ferredoxin (Fd) to plastoquinone (PQ) and proton pumping from cytoplasm to the lumen that drives the ATP production. NDH-1L-dependent CEF increases the ATP/NADPH ratio, and is therefore pivotal for oxygenic phototrophs to function under stress. Here we report two structures of NDH-1L from Thermosynechococcus elongatus BP-1, in complex with one Fd and an endogenous PQ, respectively. Our structures represent the complete model of cyanobacterial NDH-1L, revealing the binding manner of NDH-1L with Fd and PQ, as well as the structural elements crucial for proper functioning of the NDH-1L complex. Together, our data provides deep insights into the electron transport from Fd to PQ, and its coupling with proton translocation in NDH-1L.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Carotenoids / chemistry
  • Cell Membrane / chemistry
  • Electron Transport
  • Electron Transport Complex I / chemistry*
  • Electron Transport Complex I / ultrastructure
  • Ferredoxins / chemistry
  • Ferredoxins / metabolism
  • Hydrophobic and Hydrophilic Interactions
  • Lipids / chemistry
  • Models, Molecular
  • NADPH Dehydrogenase / chemistry*
  • NADPH Dehydrogenase / ultrastructure
  • Photosynthesis*
  • Plastoquinone / chemistry
  • Plastoquinone / metabolism
  • Protein Domains
  • Protein Subunits / chemistry
  • Structural Homology, Protein
  • Thermus / enzymology*

Substances

  • Ferredoxins
  • Lipids
  • Protein Subunits
  • Carotenoids
  • NADPH Dehydrogenase
  • Electron Transport Complex I
  • Plastoquinone