Mutagenesis of the D-E loop of photosystem II reaction centre protein D1. Function and assembly of photosystem II

Mutagenesis of the D-E loop of photosystem II reaction centre protein D1. Function and assembly... The sequence connecting α-helices D and E of the D1 protein in photosystem II (PSII) is longer than that found in the corresponding loop of the L subunit in the rhodobacterial reaction centre. This sequence was mutated in order to determine its role in oxygenic photosynthesis. Site-specific mutants, including point mutations and deletions of different size, of the PEST-like region and the putative cleavage area in the D-E loop of the D1 protein were constructed in Synechocystis sp. PCC 6803. The effects of mutations on the functional and structural properties of PSII and turnover of the D1 protein were examined. Our results demonstrate that deletion of either the PEST-like sequence ( Δ R225-F239) or the putative cleavage region ( Δ G240-V249, Δ R225-V249) of the D1 protein resulted in severe perturbations on the function of the QB electron acceptor of PSII. However, PSII centres of the mutant with deleted PEST region remained functional enough to support autotrophic growth whereas deletions of the putative cleavage region prevented autotrophic growth. Although enhanced degradation rates of the mutant D1 proteins under low-light growth conditions demonstrate that neither the PEST-like sequence nor the putative cleavage region are required for D1 proteolysis, it became clear that the extension in the D-E loop of the D1 protein is essential for proper PSII assembly and photoautotrophic growth. Moreover, modifications of the D-E loop resulted in transcriptional activation of the psbA gene, indicating that neither light intensity, as such, nor the activity of the electron transfer chain are the only determinants in regulation of psbA gene transcription. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Plant Molecular Biology Springer Journals

Mutagenesis of the D-E loop of photosystem II reaction centre protein D1. Function and assembly of photosystem II

Loading next page...
 
/lp/springer_journal/mutagenesis-of-the-d-e-loop-of-photosystem-ii-reaction-centre-protein-gJFzbb60U0
Publisher
Springer Journals
Copyright
Copyright © 1997 by Kluwer Academic Publishers
Subject
Life Sciences; Biochemistry, general; Plant Sciences; Plant Pathology
ISSN
0167-4412
eISSN
1573-5028
D.O.I.
10.1023/A:1005765305956
Publisher site
See Article on Publisher Site

Abstract

The sequence connecting α-helices D and E of the D1 protein in photosystem II (PSII) is longer than that found in the corresponding loop of the L subunit in the rhodobacterial reaction centre. This sequence was mutated in order to determine its role in oxygenic photosynthesis. Site-specific mutants, including point mutations and deletions of different size, of the PEST-like region and the putative cleavage area in the D-E loop of the D1 protein were constructed in Synechocystis sp. PCC 6803. The effects of mutations on the functional and structural properties of PSII and turnover of the D1 protein were examined. Our results demonstrate that deletion of either the PEST-like sequence ( Δ R225-F239) or the putative cleavage region ( Δ G240-V249, Δ R225-V249) of the D1 protein resulted in severe perturbations on the function of the QB electron acceptor of PSII. However, PSII centres of the mutant with deleted PEST region remained functional enough to support autotrophic growth whereas deletions of the putative cleavage region prevented autotrophic growth. Although enhanced degradation rates of the mutant D1 proteins under low-light growth conditions demonstrate that neither the PEST-like sequence nor the putative cleavage region are required for D1 proteolysis, it became clear that the extension in the D-E loop of the D1 protein is essential for proper PSII assembly and photoautotrophic growth. Moreover, modifications of the D-E loop resulted in transcriptional activation of the psbA gene, indicating that neither light intensity, as such, nor the activity of the electron transfer chain are the only determinants in regulation of psbA gene transcription.

Journal

Plant Molecular BiologySpringer Journals

Published: Oct 14, 2004

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off