Reinterpretation of the electron density at the site of the eighth bacteriochlorophyll in the FMO protein from Pelodictyon phaeum

Dale E. Tronrud, James Paul Allen

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

The Fenna-Matthews-Olson antenna protein from the green bacterium Pelodictyon phaeum mediates the energy transfer from a peripheral antenna complex to the membrane-bound reaction center. The three-dimensional structure of this protein has been previously modeled using X-ray diffraction to a resolution limit of 2.0 Å, with R work and R free values of 16.6 and 19.9 %, respectively (Larson et al., Photosynth Res 107:139-150, 2011). This model shows the protein as consisting of β-sheets surrounding several bacteriochlorophyll cofactors. While most of the model clearly matches the electron density maps, in this paper we re-examine the electron density for a specific feature, namely the eighth bacteriochlorophyll a cofactor. This electron density is now interpreted as arising primarily from the end of an otherwise disordered polyethylene glycol molecule. Additional electron density is present but the density is weak and cannot be unambiguously assigned. The new model has R work and R free values of 16.2 and 19.0 %, respectively.

Original languageEnglish
Pages (from-to)71-74
Number of pages4
JournalPhotosynthesis Research
Volume112
Issue number1
DOIs
Publication statusPublished - Apr 2012

Fingerprint

Pelodictyon phaeum
Bacteriochlorophylls
Carrier concentration
electrons
Electrons
Proteins
proteins
antennae
Antennas
Energy Transfer
X-Ray Diffraction
Energy transfer
protein structure
Bacteria
energy transfer
polyethylene glycol
X-ray diffraction
Membranes
X ray diffraction
Molecules

Keywords

  • Energy transfer
  • Green bacteria
  • Light harvesting complex
  • Three-dimensional structure

ASJC Scopus subject areas

  • Plant Science
  • Cell Biology
  • Biochemistry

Cite this

@article{0bddaefdefd2495a8d96b72d09b8a4bb,
title = "Reinterpretation of the electron density at the site of the eighth bacteriochlorophyll in the FMO protein from Pelodictyon phaeum",
abstract = "The Fenna-Matthews-Olson antenna protein from the green bacterium Pelodictyon phaeum mediates the energy transfer from a peripheral antenna complex to the membrane-bound reaction center. The three-dimensional structure of this protein has been previously modeled using X-ray diffraction to a resolution limit of 2.0 {\AA}, with R work and R free values of 16.6 and 19.9 {\%}, respectively (Larson et al., Photosynth Res 107:139-150, 2011). This model shows the protein as consisting of β-sheets surrounding several bacteriochlorophyll cofactors. While most of the model clearly matches the electron density maps, in this paper we re-examine the electron density for a specific feature, namely the eighth bacteriochlorophyll a cofactor. This electron density is now interpreted as arising primarily from the end of an otherwise disordered polyethylene glycol molecule. Additional electron density is present but the density is weak and cannot be unambiguously assigned. The new model has R work and R free values of 16.2 and 19.0 {\%}, respectively.",
keywords = "Energy transfer, Green bacteria, Light harvesting complex, Three-dimensional structure",
author = "Tronrud, {Dale E.} and Allen, {James Paul}",
year = "2012",
month = "4",
doi = "10.1007/s11120-012-9735-8",
language = "English",
volume = "112",
pages = "71--74",
journal = "Photosynthesis Research",
issn = "0166-8595",
publisher = "Springer Netherlands",
number = "1",

}

TY - JOUR

T1 - Reinterpretation of the electron density at the site of the eighth bacteriochlorophyll in the FMO protein from Pelodictyon phaeum

AU - Tronrud, Dale E.

AU - Allen, James Paul

PY - 2012/4

Y1 - 2012/4

N2 - The Fenna-Matthews-Olson antenna protein from the green bacterium Pelodictyon phaeum mediates the energy transfer from a peripheral antenna complex to the membrane-bound reaction center. The three-dimensional structure of this protein has been previously modeled using X-ray diffraction to a resolution limit of 2.0 Å, with R work and R free values of 16.6 and 19.9 %, respectively (Larson et al., Photosynth Res 107:139-150, 2011). This model shows the protein as consisting of β-sheets surrounding several bacteriochlorophyll cofactors. While most of the model clearly matches the electron density maps, in this paper we re-examine the electron density for a specific feature, namely the eighth bacteriochlorophyll a cofactor. This electron density is now interpreted as arising primarily from the end of an otherwise disordered polyethylene glycol molecule. Additional electron density is present but the density is weak and cannot be unambiguously assigned. The new model has R work and R free values of 16.2 and 19.0 %, respectively.

AB - The Fenna-Matthews-Olson antenna protein from the green bacterium Pelodictyon phaeum mediates the energy transfer from a peripheral antenna complex to the membrane-bound reaction center. The three-dimensional structure of this protein has been previously modeled using X-ray diffraction to a resolution limit of 2.0 Å, with R work and R free values of 16.6 and 19.9 %, respectively (Larson et al., Photosynth Res 107:139-150, 2011). This model shows the protein as consisting of β-sheets surrounding several bacteriochlorophyll cofactors. While most of the model clearly matches the electron density maps, in this paper we re-examine the electron density for a specific feature, namely the eighth bacteriochlorophyll a cofactor. This electron density is now interpreted as arising primarily from the end of an otherwise disordered polyethylene glycol molecule. Additional electron density is present but the density is weak and cannot be unambiguously assigned. The new model has R work and R free values of 16.2 and 19.0 %, respectively.

KW - Energy transfer

KW - Green bacteria

KW - Light harvesting complex

KW - Three-dimensional structure

UR - http://www.scopus.com/inward/record.url?scp=84859757695&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84859757695&partnerID=8YFLogxK

U2 - 10.1007/s11120-012-9735-8

DO - 10.1007/s11120-012-9735-8

M3 - Article

C2 - 22457093

AN - SCOPUS:84859757695

VL - 112

SP - 71

EP - 74

JO - Photosynthesis Research

JF - Photosynthesis Research

SN - 0166-8595

IS - 1

ER -