Deletion of the PEST-like region of photosystem two modifies the QB-binding pocket but does not prevent rapid turnover of D1

Peter J. Nixon, Josef Komenda, James Barber, Z. Deák, I. Vass, Bruce A. Diner

Research output: Contribution to journalArticle

54 Citations (Scopus)

Abstract

The rapid turn-over of the D1 polypeptide of the photosystem two complex has been suggested to be due to the presence of a "PEST"-like sequence located between putative transmembrane helices IV and V of D1 (Greenberg, B. M., Gaba, V., Mattoo, A. K. and Edelman, M. (1987) EMBO J. 6, 2865-2869). We have tested this hypothesis by constructing a deletion mutant (Δ226-233) of the cyanobacterium Synechocystis sp. PCC 6803 in which residues 226-233 of the D1 polypeptide, containing the PEST-like sequence, have been removed. The resulting mutant, ΔPEST, is able to grow photoautotrophically and give light-saturated rates of oxygen at wild type levels. However electron transfer on the acceptor side of the complex is perturbed. Analysis of cells by thermoluminescence and by monitoring the decay in quantum yield of variable fluorescence following saturating flash excitation indicates that QB-, but not QA-, is destabilized in this mutant. Electron transfer on the donor side of photosystem two remains largely unchanged in the mutant. Turnover of the D1 polypeptide as examined by pulse-chase experiments using [35S] methionine was enhanced in the ΔPEST mutant compared to strain TC31 which is the wild type control. We conclude that the PEST sequence is not absolutely required for turnover of the D1 polypeptide in vivo although deletion of residues 226-233 does have an effect on the redox equilibrium between QA and QB.

Original languageEnglish
Pages (from-to)14919-14927
Number of pages9
JournalJournal of Biological Chemistry
Volume270
Issue number25
Publication statusPublished - Jun 23 1995

Fingerprint

Peptides
Electrons
Synechocystis
Thermoluminescence
Cyanobacteria
Quantum yield
Methionine
Oxidation-Reduction
Fluorescence
Oxygen
Light
Monitoring
Experiments

ASJC Scopus subject areas

  • Biochemistry

Cite this

Deletion of the PEST-like region of photosystem two modifies the QB-binding pocket but does not prevent rapid turnover of D1. / Nixon, Peter J.; Komenda, Josef; Barber, James; Deák, Z.; Vass, I.; Diner, Bruce A.

In: Journal of Biological Chemistry, Vol. 270, No. 25, 23.06.1995, p. 14919-14927.

Research output: Contribution to journalArticle

@article{b5ef1c9b618d40278c190d28534f3a2e,
title = "Deletion of the PEST-like region of photosystem two modifies the QB-binding pocket but does not prevent rapid turnover of D1",
abstract = "The rapid turn-over of the D1 polypeptide of the photosystem two complex has been suggested to be due to the presence of a {"}PEST{"}-like sequence located between putative transmembrane helices IV and V of D1 (Greenberg, B. M., Gaba, V., Mattoo, A. K. and Edelman, M. (1987) EMBO J. 6, 2865-2869). We have tested this hypothesis by constructing a deletion mutant (Δ226-233) of the cyanobacterium Synechocystis sp. PCC 6803 in which residues 226-233 of the D1 polypeptide, containing the PEST-like sequence, have been removed. The resulting mutant, ΔPEST, is able to grow photoautotrophically and give light-saturated rates of oxygen at wild type levels. However electron transfer on the acceptor side of the complex is perturbed. Analysis of cells by thermoluminescence and by monitoring the decay in quantum yield of variable fluorescence following saturating flash excitation indicates that QB-, but not QA-, is destabilized in this mutant. Electron transfer on the donor side of photosystem two remains largely unchanged in the mutant. Turnover of the D1 polypeptide as examined by pulse-chase experiments using [35S] methionine was enhanced in the ΔPEST mutant compared to strain TC31 which is the wild type control. We conclude that the PEST sequence is not absolutely required for turnover of the D1 polypeptide in vivo although deletion of residues 226-233 does have an effect on the redox equilibrium between QA and QB.",
author = "Nixon, {Peter J.} and Josef Komenda and James Barber and Z. De{\'a}k and I. Vass and Diner, {Bruce A.}",
year = "1995",
month = "6",
day = "23",
language = "English",
volume = "270",
pages = "14919--14927",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "25",

}

TY - JOUR

T1 - Deletion of the PEST-like region of photosystem two modifies the QB-binding pocket but does not prevent rapid turnover of D1

AU - Nixon, Peter J.

AU - Komenda, Josef

AU - Barber, James

AU - Deák, Z.

AU - Vass, I.

AU - Diner, Bruce A.

PY - 1995/6/23

Y1 - 1995/6/23

N2 - The rapid turn-over of the D1 polypeptide of the photosystem two complex has been suggested to be due to the presence of a "PEST"-like sequence located between putative transmembrane helices IV and V of D1 (Greenberg, B. M., Gaba, V., Mattoo, A. K. and Edelman, M. (1987) EMBO J. 6, 2865-2869). We have tested this hypothesis by constructing a deletion mutant (Δ226-233) of the cyanobacterium Synechocystis sp. PCC 6803 in which residues 226-233 of the D1 polypeptide, containing the PEST-like sequence, have been removed. The resulting mutant, ΔPEST, is able to grow photoautotrophically and give light-saturated rates of oxygen at wild type levels. However electron transfer on the acceptor side of the complex is perturbed. Analysis of cells by thermoluminescence and by monitoring the decay in quantum yield of variable fluorescence following saturating flash excitation indicates that QB-, but not QA-, is destabilized in this mutant. Electron transfer on the donor side of photosystem two remains largely unchanged in the mutant. Turnover of the D1 polypeptide as examined by pulse-chase experiments using [35S] methionine was enhanced in the ΔPEST mutant compared to strain TC31 which is the wild type control. We conclude that the PEST sequence is not absolutely required for turnover of the D1 polypeptide in vivo although deletion of residues 226-233 does have an effect on the redox equilibrium between QA and QB.

AB - The rapid turn-over of the D1 polypeptide of the photosystem two complex has been suggested to be due to the presence of a "PEST"-like sequence located between putative transmembrane helices IV and V of D1 (Greenberg, B. M., Gaba, V., Mattoo, A. K. and Edelman, M. (1987) EMBO J. 6, 2865-2869). We have tested this hypothesis by constructing a deletion mutant (Δ226-233) of the cyanobacterium Synechocystis sp. PCC 6803 in which residues 226-233 of the D1 polypeptide, containing the PEST-like sequence, have been removed. The resulting mutant, ΔPEST, is able to grow photoautotrophically and give light-saturated rates of oxygen at wild type levels. However electron transfer on the acceptor side of the complex is perturbed. Analysis of cells by thermoluminescence and by monitoring the decay in quantum yield of variable fluorescence following saturating flash excitation indicates that QB-, but not QA-, is destabilized in this mutant. Electron transfer on the donor side of photosystem two remains largely unchanged in the mutant. Turnover of the D1 polypeptide as examined by pulse-chase experiments using [35S] methionine was enhanced in the ΔPEST mutant compared to strain TC31 which is the wild type control. We conclude that the PEST sequence is not absolutely required for turnover of the D1 polypeptide in vivo although deletion of residues 226-233 does have an effect on the redox equilibrium between QA and QB.

UR - http://www.scopus.com/inward/record.url?scp=0029011524&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029011524&partnerID=8YFLogxK

M3 - Article

C2 - 7797471

AN - SCOPUS:0029011524

VL - 270

SP - 14919

EP - 14927

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 25

ER -