Nanodissection and high-resolution imaging of the Rhodopseudomonas viridis photosynthetic core complex in native membranes by AFM Academic Article uri icon

Overview

MeSH Major

  • Nanotechnology
  • Photosynthetic Reaction Center Complex Proteins
  • Rhodopseudomonas

abstract

  • In photosynthesis, highly organized multiprotein assemblies convert sunlight into biochemical energy with high efficiency. A challenge in structural biology is to analyze such supramolecular complexes in native membranes. Atomic force microscopy (AFM) with high lateral resolution, high signal-to-noise ratio, and the possibility to nanodissect biological samples is a unique tool to investigate multiprotein complexes at molecular resolution in situ. Here we present high-resolution AFM of the photosynthetic core complex in native Rhodopseudomonas viridis membranes. Topographs at 10-A lateral and approximately 1-A vertical resolution reveal a single reaction center (RC) surrounded by a closed ellipsoid of 16 light-harvesting (LH1) subunits. Nanodissection of the tetraheme cytochrome (4Hcyt) subunit from the RC allows demonstration that the L and M subunits exhibit an asymmetric topography intimately associated to the LH1 subunits located at the short ellipsis axis. This architecture implies a distance distribution between the antenna and the RC compared with a centered location of the RC within a circular LH1, which may influence the energy transfer within the core complex. The LH1 subunits rearrange into a circle after removal of the RC from the core complex.

publication date

  • February 18, 2003

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC149894

Digital Object Identifier (DOI)

  • 10.1073/pnas.0437992100

PubMed ID

  • 12574504

Additional Document Info

start page

  • 1690

end page

  • 3

volume

  • 100

number

  • 4