Mutation of histidine residues in CP47 leads to destabilization of the photosystem II complex and to impairment of light energy transfer

Gaozhong Shen, Julian J. Eaton-Rye, Willem Vermaas

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

Site-directed mutagenesis has been used to change conserved histidine residues in hydrophobic regions of the photosystem II chlorophyll-binding protein CP47 in the cyanobacterium Synechocystis sp. PCC 6803. Nine mutants with one, four mutants with two, and four mutants with three His mutations in CP47 have been generated and characterized. Mutation of any one of seven different His residues to Tyr leads to slower photoautotrophic growth and apparent destabilization of the PS II complex. Mutations introduced into multiple His residues in one mutant exhibited a cumulative effect. Replacing His by Asn leads to a much smaller effect than observed upon mutation to Tyr. This is consistent with the hypothesis that the mutated His residues are chlorophyll ligands: Asn can substitute as chlorophyll ligand, whereas Tyr cannot. Further evidence supporting a role of the mutated His residues in chlorophyll binding comes from measurements of the light intensity needed to half-saturate oxygen evolution. All His mutants with impaired PS II function needed higher light intensities for half-saturation than wild type. A possible explanation for this decrease in antenna efficiency in the mutants is a loss of the Mg in the chlorophyll due to a loss of the fifth ligand, and thus the formation of a pheophytin molecule in the antenna. We conclude that conserved His residues in hydrophobic regions of CP47 indeed are chlorophyll ligands and that these ligands are important for PS II stability as well as efficient antenna function.

Original languageEnglish (US)
Pages (from-to)5109-5115
Number of pages7
JournalBiochemistry
Volume32
Issue number19
StatePublished - 1993

Fingerprint

Photosystem II Protein Complex
Energy Transfer
Chlorophyll
Histidine
Energy transfer
Ligands
Mutation
Antennas
Pheophytins
Chlorophyll Binding Proteins
High intensity light
Synechocystis
Light
Mutagenesis
Cyanobacteria
Site-Directed Mutagenesis
Oxygen
Molecules
Growth

ASJC Scopus subject areas

  • Biochemistry

Cite this

Mutation of histidine residues in CP47 leads to destabilization of the photosystem II complex and to impairment of light energy transfer. / Shen, Gaozhong; Eaton-Rye, Julian J.; Vermaas, Willem.

In: Biochemistry, Vol. 32, No. 19, 1993, p. 5109-5115.

Research output: Contribution to journalArticle

@article{04f9d05cabb146a9b4c6f91c19bae400,
title = "Mutation of histidine residues in CP47 leads to destabilization of the photosystem II complex and to impairment of light energy transfer",
abstract = "Site-directed mutagenesis has been used to change conserved histidine residues in hydrophobic regions of the photosystem II chlorophyll-binding protein CP47 in the cyanobacterium Synechocystis sp. PCC 6803. Nine mutants with one, four mutants with two, and four mutants with three His mutations in CP47 have been generated and characterized. Mutation of any one of seven different His residues to Tyr leads to slower photoautotrophic growth and apparent destabilization of the PS II complex. Mutations introduced into multiple His residues in one mutant exhibited a cumulative effect. Replacing His by Asn leads to a much smaller effect than observed upon mutation to Tyr. This is consistent with the hypothesis that the mutated His residues are chlorophyll ligands: Asn can substitute as chlorophyll ligand, whereas Tyr cannot. Further evidence supporting a role of the mutated His residues in chlorophyll binding comes from measurements of the light intensity needed to half-saturate oxygen evolution. All His mutants with impaired PS II function needed higher light intensities for half-saturation than wild type. A possible explanation for this decrease in antenna efficiency in the mutants is a loss of the Mg in the chlorophyll due to a loss of the fifth ligand, and thus the formation of a pheophytin molecule in the antenna. We conclude that conserved His residues in hydrophobic regions of CP47 indeed are chlorophyll ligands and that these ligands are important for PS II stability as well as efficient antenna function.",
author = "Gaozhong Shen and Eaton-Rye, {Julian J.} and Willem Vermaas",
year = "1993",
language = "English (US)",
volume = "32",
pages = "5109--5115",
journal = "Biochemistry",
issn = "0006-2960",
publisher = "American Chemical Society",
number = "19",

}

TY - JOUR

T1 - Mutation of histidine residues in CP47 leads to destabilization of the photosystem II complex and to impairment of light energy transfer

AU - Shen, Gaozhong

AU - Eaton-Rye, Julian J.

AU - Vermaas, Willem

PY - 1993

Y1 - 1993

N2 - Site-directed mutagenesis has been used to change conserved histidine residues in hydrophobic regions of the photosystem II chlorophyll-binding protein CP47 in the cyanobacterium Synechocystis sp. PCC 6803. Nine mutants with one, four mutants with two, and four mutants with three His mutations in CP47 have been generated and characterized. Mutation of any one of seven different His residues to Tyr leads to slower photoautotrophic growth and apparent destabilization of the PS II complex. Mutations introduced into multiple His residues in one mutant exhibited a cumulative effect. Replacing His by Asn leads to a much smaller effect than observed upon mutation to Tyr. This is consistent with the hypothesis that the mutated His residues are chlorophyll ligands: Asn can substitute as chlorophyll ligand, whereas Tyr cannot. Further evidence supporting a role of the mutated His residues in chlorophyll binding comes from measurements of the light intensity needed to half-saturate oxygen evolution. All His mutants with impaired PS II function needed higher light intensities for half-saturation than wild type. A possible explanation for this decrease in antenna efficiency in the mutants is a loss of the Mg in the chlorophyll due to a loss of the fifth ligand, and thus the formation of a pheophytin molecule in the antenna. We conclude that conserved His residues in hydrophobic regions of CP47 indeed are chlorophyll ligands and that these ligands are important for PS II stability as well as efficient antenna function.

AB - Site-directed mutagenesis has been used to change conserved histidine residues in hydrophobic regions of the photosystem II chlorophyll-binding protein CP47 in the cyanobacterium Synechocystis sp. PCC 6803. Nine mutants with one, four mutants with two, and four mutants with three His mutations in CP47 have been generated and characterized. Mutation of any one of seven different His residues to Tyr leads to slower photoautotrophic growth and apparent destabilization of the PS II complex. Mutations introduced into multiple His residues in one mutant exhibited a cumulative effect. Replacing His by Asn leads to a much smaller effect than observed upon mutation to Tyr. This is consistent with the hypothesis that the mutated His residues are chlorophyll ligands: Asn can substitute as chlorophyll ligand, whereas Tyr cannot. Further evidence supporting a role of the mutated His residues in chlorophyll binding comes from measurements of the light intensity needed to half-saturate oxygen evolution. All His mutants with impaired PS II function needed higher light intensities for half-saturation than wild type. A possible explanation for this decrease in antenna efficiency in the mutants is a loss of the Mg in the chlorophyll due to a loss of the fifth ligand, and thus the formation of a pheophytin molecule in the antenna. We conclude that conserved His residues in hydrophobic regions of CP47 indeed are chlorophyll ligands and that these ligands are important for PS II stability as well as efficient antenna function.

UR - http://www.scopus.com/inward/record.url?scp=0027198655&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027198655&partnerID=8YFLogxK

M3 - Article

C2 - 8494886

AN - SCOPUS:0027198655

VL - 32

SP - 5109

EP - 5115

JO - Biochemistry

JF - Biochemistry

SN - 0006-2960

IS - 19

ER -