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Over Expression of the Cyanobacterial Pgr5-Homologue Leads to Pseudoreversion in a Gene Coding for a Putative Esterase in Synechocystis 6803. Life (Basel) 2020; 10:life10090174. [PMID: 32899164 PMCID: PMC7555055 DOI: 10.3390/life10090174] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/31/2020] [Accepted: 09/01/2020] [Indexed: 01/13/2023] Open
Abstract
Pgr5 proteins play a major direct role in cyclic electron flow paths in plants and eukaryotic phytoplankton. The genomes of many cyanobacterial species code for Pgr5-like proteins but their function is still uncertain. Here, we present evidence that supports a link between the Synechocystis sp. PCC6803 Pgr5-like protein and the regulation of intracellular redox balance. The knockout strain, pgr5KO, did not display substantial phenotypic response under our experimental conditions, confirming results obtained in earlier studies. However, the overexpression strain, pgr5OE, accumulated 2.5-fold more chlorophyll than the wild type and displayed increased content of photosystems matching the chlorophyll increase. As a result, electron transfer rates through the photosynthetic apparatus of pgr5OE increased, as did the amount of energy stored as glycogen. While, under photoautotrophic conditions, this metabolic difference had only minor effects, under mixotrophic conditions, pgr5OE cultures collapsed. Interestingly, this specific phenotype of pgr5OE mutants displayed a tendency for reverting, and cultures which previously collapsed in the presence of glucose were now able to survive. DNA sequencing of a pgr5OE strain revealed a second site suppression mutation in slr1916, a putative esterase associated with redox regulation. The phenotype of the slr1916 knockout is very similar to that of the strain reported here and to that of the pmgA regulator knockout. These data demonstrate that, in Synechocystis 6803, there is strong selection against overexpression of the Pgr5-like protein. The pseudoreversion event in a gene involved in redox regulation suggests a connection of the Pgr5-like protein to this network.
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Damrow R, Maldener I, Zilliges Y. The Multiple Functions of Common Microbial Carbon Polymers, Glycogen and PHB, during Stress Responses in the Non-Diazotrophic Cyanobacterium Synechocystis sp. PCC 6803. Front Microbiol 2016; 7:966. [PMID: 27446007 PMCID: PMC4914499 DOI: 10.3389/fmicb.2016.00966] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 06/03/2016] [Indexed: 12/31/2022] Open
Abstract
Classical microbial carbon polymers such as glycogen and polyhydroxybutyrate (PHB) have a crucial impact as both a sink and a reserve under macronutrient stress conditions. Most microbial species exclusively synthesize and degrade either glycogen or PHB. A few bacteria such as the phototrophic model organism Synechocystis sp. PCC 6803 surprisingly produce both physico-chemically different polymers under conditions of high C to N ratios. For the first time, the function and interrelation of both carbon polymers in non-diazotrophic cyanobacteria are analyzed in a comparative physiological study of single- and double-knockout mutants (ΔglgC; ΔphaC; ΔglgC/ΔphaC), respectively. Most of the observed phenotypes are explicitly related to the knockout of glycogen synthesis, highlighting the metabolic, energetic, and structural impact of this process whenever cells switch from an active, photosynthetic 'protein status' to a dormant 'glycogen status'. The carbon flux regulation into glycogen granules is apparently crucial for both phycobilisome degradation and thylakoid layer disassembly in the presence of light. In contrast, PHB synthesis is definitely not involved in this primary acclimation response. Moreover, the very weak interrelations between the two carbon-polymer syntheses indicate that the regulation and role of PHB synthesis in Synechocystis sp. PCC 6803 is different from glycogen synthesis.
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Affiliation(s)
- Ramon Damrow
- Section of Plant Biochemistry, Institute of Biology, Humboldt-Universität zu Berlin Berlin, Germany
| | - Iris Maldener
- Section of Organismic Interactions, Interfaculty Institute of Microbiology and Infection Medicine, Eberhard Karls Universität Tübingen Tübingen, Germany
| | - Yvonne Zilliges
- Section of Plant Biochemistry, Institute of Biology, Humboldt-Universität zu BerlinBerlin, Germany; Section of Biophysics and Photosynthesis, Institute of Physics, Freie Universität BerlinBerlin, Germany
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3
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Gründel M, Scheunemann R, Lockau W, Zilliges Y. Impaired glycogen synthesis causes metabolic overflow reactions and affects stress responses in the cyanobacterium Synechocystis sp. PCC 6803. Microbiology (Reading) 2012; 158:3032-3043. [DOI: 10.1099/mic.0.062950-0] [Citation(s) in RCA: 187] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Marianne Gründel
- Humboldt-Universität zu Berlin, Institute of Biology/Biochemistry of Plants, Chausseestr. 117, 10115 Berlin, Germany
| | - Ramon Scheunemann
- Humboldt-Universität zu Berlin, Institute of Biology/Biochemistry of Plants, Chausseestr. 117, 10115 Berlin, Germany
| | - Wolfgang Lockau
- Humboldt-Universität zu Berlin, Institute of Biology/Biochemistry of Plants, Chausseestr. 117, 10115 Berlin, Germany
| | - Yvonne Zilliges
- Humboldt-Universität zu Berlin, Institute of Biology/Biochemistry of Plants, Chausseestr. 117, 10115 Berlin, Germany
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Rediger A, Geißen R, Steuten B, Heilmann B, Wagner R, Axmann IM. 6S RNA - an old issue became blue-green. MICROBIOLOGY-SGM 2012; 158:2480-2491. [PMID: 22767549 DOI: 10.1099/mic.0.058958-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
6S RNA from Escherichia coli acts as a versatile transcriptional regulator by binding to the RNA polymerase and changing promoter selectivity. Although homologous 6S RNA structures exist in a wide range of bacteria, including cyanobacteria, our knowledge of 6S RNA function results almost exclusively from studies with E. coli. To test for potential structural and functional conservation, we selected four predicted cyanobacterial 6S RNAs (Synechocystis, Synechococcus, Prochlorococcus and Nostoc), which we compared with their E. coli counterpart. Temperature-gradient gel electrophoresis revealed similar thermodynamic transition profiles for all 6S RNAs, indicating basically similar secondary structures. Subtle differences in melting behaviour of the different RNAs point to minor structural variations possibly linked to differences in optimal growth temperature. Secondary structural analysis of three cyanobacterial 6S RNAs employing limited enzymic hydrolysis and in-line probing supported the predicted high degree of secondary structure conservation. Testing for functional homology we found that all cyanobacterial 6S RNAs were active in binding E. coli RNA polymerase and transcriptional inhibition, and had the ability to act as template for transcription of product RNAs (pRNAs). Deletion of the 6S RNA gene in Synechocystis did not significantly affect cell growth in liquid media but reduced fitness during growth on solid agar. While our study shows that basic 6S RNA functions are conserved in species as distantly related as E. coli and cyanobacteria, we also noted a subtle degree of divergence, which might reflect fundamental differences in transcriptional regulation and lifestyle, thus providing the first evidence for a possible physiological role in cyanobacteria.
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Affiliation(s)
- Anne Rediger
- Institute for Theoretical Biology, Charité-Universitätsmedizin, Invalidenstraße 43, D-10115 Berlin, Germany
| | - René Geißen
- Molecular Biology of Bacteria, Heinrich-Heine University Düsseldorf, Universitätsstr. 1, D-40225 Düsseldorf, Germany
| | - Benedikt Steuten
- Molecular Biology of Bacteria, Heinrich-Heine University Düsseldorf, Universitätsstr. 1, D-40225 Düsseldorf, Germany
| | - Beate Heilmann
- Institute for Theoretical Biology, Charité-Universitätsmedizin, Invalidenstraße 43, D-10115 Berlin, Germany
| | - Rolf Wagner
- Molecular Biology of Bacteria, Heinrich-Heine University Düsseldorf, Universitätsstr. 1, D-40225 Düsseldorf, Germany
| | - Ilka M Axmann
- Institute for Theoretical Biology, Charité-Universitätsmedizin, Invalidenstraße 43, D-10115 Berlin, Germany
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Requirements for construction of a functional hybrid complex of photosystem I and [NiFe]-hydrogenase. Appl Environ Microbiol 2010; 76:2641-51. [PMID: 20154103 DOI: 10.1128/aem.02700-09] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The development of cellular systems in which the enzyme hydrogenase is efficiently coupled to the oxygenic photosynthesis apparatus represents an attractive avenue to produce H(2) sustainably from light and water. Here we describe the molecular design of the individual components required for the direct coupling of the O(2)-tolerant membrane-bound hydrogenase (MBH) from Ralstonia eutropha H16 to the acceptor site of photosystem I (PS I) from Synechocystis sp. PCC 6803. By genetic engineering, the peripheral subunit PsaE of PS I was fused to the MBH, and the resulting hybrid protein was purified from R. eutropha to apparent homogeneity via two independent affinity chromatographical steps. The catalytically active MBH-PsaE (MBH(PsaE)) hybrid protein could be isolated only from the cytoplasmic fraction. This was surprising, since the MBH is a substrate of the twin-arginine translocation system and was expected to reside in the periplasm. We conclude that the attachment of the additional PsaE domain to the small, electron-transferring subunit of the MBH completely abolished the export competence of the protein. Activity measurements revealed that the H(2) production capacity of the purified MBH(PsaE) fusion protein was very similar to that of wild-type MBH. In order to analyze the specific interaction of MBH(PsaE) with PS I, His-tagged PS I lacking the PsaE subunit was purified via Ni-nitrilotriacetic acid affinity and subsequent hydrophobic interaction chromatography. Formation of PS I-hydrogenase supercomplexes was demonstrated by blue native gel electrophoresis. The results indicate a vital prerequisite for the quantitative analysis of the MBH(PsaE)-PS I complex formation and its light-driven H(2) production capacity by means of spectroelectrochemistry.
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Dienst D, Dühring U, Mollenkopf HJ, Vogel J, Golecki J, Hess WR, Wilde A. The cyanobacterial homologue of the RNA chaperone Hfq is essential for motility of Synechocystis sp. PCC 6803. MICROBIOLOGY-SGM 2008; 154:3134-3143. [PMID: 18832319 DOI: 10.1099/mic.0.2008/020222-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The ssr3341 locus was previously suggested to encode an orthologue of the RNA chaperone Hfq in the cyanobacterium Synechocystis sp. strain PCC 6803. Insertional inactivation of this gene resulted in a mutant that was not naturally transformable and exhibited a non-phototactic phenotype compared with the wild-type. The loss of motility was complemented by reintroduction of the wild-type gene, correlated with the re-establishment of type IV pili on the cell surface. Microarray analyses revealed a small set of genes with drastically reduced transcript levels in the knockout mutant compared with the wild-type cells. Among the most strongly affected genes, slr1667, slr1668, slr2015, slr2016 and slr2018 stood out, as they belong to two operons that had previously been shown to be involved in motility, controlled by the cAMP receptor protein SYCRP1. This suggests a link between cAMP signalling, motility and possibly the involvement of RNA-based regulation. This is believed to be the first report demonstrating a functional role of an Hfq orthologue in cyanobacteria, establishing a new factor in the control of motility.
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Affiliation(s)
- Dennis Dienst
- Humboldt-University Berlin, Institute of Biology, Chausseestr. 117, 10115 Berlin, Germany
| | - Ulf Dühring
- Humboldt-University Berlin, Institute of Biology, Chausseestr. 117, 10115 Berlin, Germany
| | | | - Jörg Vogel
- Max Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany
| | - Jochen Golecki
- University of Freiburg, Faculty of Biology, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Wolfgang R Hess
- University of Freiburg, Faculty of Biology, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Annegret Wilde
- Justus-Liebig University Giessen, Institute of Microbiology and Molecular Biology, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.,Humboldt-University Berlin, Institute of Biology, Chausseestr. 117, 10115 Berlin, Germany
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Scherzinger D, Ruch S, Kloer D, Wilde A, Al-Babili S. Retinal is formed from apo-carotenoids in Nostoc sp. PCC7120: in vitro characterization of an apo-carotenoid oxygenase. Biochem J 2006; 398:361-9. [PMID: 16759173 PMCID: PMC1559462 DOI: 10.1042/bj20060592] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2006] [Revised: 06/01/2006] [Accepted: 06/07/2006] [Indexed: 11/17/2022]
Abstract
The sensory rhodopsin from Anabaena (Nostoc) sp. PCC7120 is the first cyanobacterial retinylidene protein identified. Here, we report on NosACO (Nostoc apo-carotenoid oxygenase), encoded by the ORF (open reading frame) all4284, as the candidate responsible for the formation of the required chromophore, retinal. In contrast with the enzymes from animals, NosACO converts beta-apo-carotenals instead of beta-carotene into retinal in vitro. The identity of the enzymatic products was proven by HPLC and gas chromatography-MS. NosACO exhibits a wide substrate specificity with respect to chain lengths and functional end-groups, converting beta-apo-carotenals, (3R)-3-hydroxy-beta-apo-carotenals and the corresponding alcohols into retinal and (3R)-3-hydroxyretinal respectively. However, kinetic analyses revealed very divergent Km and Vmax values. On the basis of the crystal structure of SynACO (Synechocystis sp. PCC6803 apo-carotenoid oxygenase), a related enzyme showing similar enzymatic activity, we designed a homology model of the native NosACO. The deduced structure explains the absence of beta-carotene-cleavage activity and indicates that NosACO is a monotopic membrane protein. Accordingly, NosACO could be readily reconstituted into liposomes. To localize SynACO in vivo, a Synechocystis knock-out strain was generated expressing SynACO as the sole carotenoid oxygenase. Western-blot analyses showed that the main portion of SynACO occurred in a membrane-bound form.
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Key Words
- carotenoid cleavage
- nostoc and synechocystis apo-carotenoid oxygenases (nosaco and synaco)
- cyanobacteria
- opsin
- retinal
- aba, abscisic acid
- asr, anabaena sensory rhodopsin
- 15,15′-bco (also bco i), β-β-carotene-15,15′-oxygenase
- ccd1, carotenoid cleavage dioxygenase 1
- dtt, dithiothreitol
- ei, electron impact
- gc-ms, gas chromatography–ms
- nist, national institute of standards and technology (gaithersburg, md, u.s.a.)
- nosaco, nostoc apo-carotenoid oxygenase
- orf, open reading frame
- rpe65, retinal pigment epithelium 65
- synaco, synechocystis apo-carotenoid oxygenase
- vp14, viviparous14
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Affiliation(s)
- Daniel Scherzinger
- *Albert-Ludwigs University of Freiburg, Institute of Biology II, Cell Biology, Schaenzlestrasse 1, D-79104 Freiburg, Federal Republic of Germany
| | - Sandra Ruch
- †Albert-Ludwigs University of Freiburg, Institute of Organic Chemistry and Biochemistry, Albertstrasse 1, D-79104 Freiburg, Federal Republic of Germany
| | - Daniel P. Kloer
- †Albert-Ludwigs University of Freiburg, Institute of Organic Chemistry and Biochemistry, Albertstrasse 1, D-79104 Freiburg, Federal Republic of Germany
| | - Annegret Wilde
- ‡Humboldt University Berlin, Institute of Biology, Plant Biochemistry, Chausseestrasse 117, D-10115 Berlin, Federal Republic of Germany
| | - Salim Al-Babili
- *Albert-Ludwigs University of Freiburg, Institute of Biology II, Cell Biology, Schaenzlestrasse 1, D-79104 Freiburg, Federal Republic of Germany
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Fiedler B, Börner T, Wilde A. Phototaxis in the cyanobacterium Synechocystis sp. PCC 6803: role of different photoreceptors. Photochem Photobiol 2006; 81:1481-8. [PMID: 16354116 DOI: 10.1562/2005-06-28-ra-592] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The second cyanobacterial phytochrome Cph2 from Synechocystis sp. PCC 6803 was suggested as a part of a light-stimulated signal transduction chain inhibiting movement toward blue light. Cph2 has the two bilin binding sites, cysteine-129 and cysteine-1022, that might be involved in sensing of red/far-red and blue light, respectively. Here, we present data on wavelength dependence of the phototaxis inhibition under blue light, indicating that Cph2 itself is the photoreceptor for this blue light response. We found that inhibition of blue-light phototaxis in wild-type cells occurred below the transition point of about 470 nm. Substitution of cysteine-1022 with valine led to photomovement of the cells toward blue light (cph2(-) mutant phenotype). Analysis of mutants lacking cysteine-129 in the N-terminal chromophore binding domain indicated that this domain is also important for Cph2 function or folding of the protein. Furthermore, putative blue-light and phytochrome-like photoreceptors encoded by the Synechocystis sp. PCC 6803 genome were inactivated in wild-type and cph2 knockout mutant background. Our results suggest that none of these potential photoreceptors interfere with Cph2 function, although inactivation of taxD1 as well as slr1694 encoding a BLUF protein led to cells that reversed the direction of movement under blue light illumination in mutant strains of cph2.
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Affiliation(s)
- Brita Fiedler
- Institut für Biologie, Humboldt-Universität zu Berlin, Chausseestrasse 117, 10115 Berlin, Germany
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Wilde A, Mikolajczyk S, Alawady A, Lokstein H, Grimm B. The gun4 gene is essential for cyanobacterial porphyrin metabolism. FEBS Lett 2004; 571:119-23. [PMID: 15280028 DOI: 10.1016/j.febslet.2004.06.063] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2004] [Revised: 06/16/2004] [Accepted: 06/17/2004] [Indexed: 11/20/2022]
Abstract
Ycf53 is a hypothetical chloroplast open reading frame with similarity to the Arabidopsis nuclear gene GUN4. In plants, GUN4 is involved in tetrapyrrole biosynthesis. We demonstrate that one of the two Synechocystis sp. PCC 6803 ycf53 genes with similarity to GUN4 functions in chlorophyll (Chl) biosynthesis as well: cyanobacterial gun4 mutant cells exhibit lower Chl contents, accumulate protoporphyrin IX and show less activity not only of Mg chelatase but also of Fe chelatase. The possible role of Gun4 for the Mg as well as Fe porphyrin biosynthesis branches in Synechocystis sp. PCC 6803 is discussed.
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Affiliation(s)
- Annegret Wilde
- Institut für Biologie, Biochemie der Pflanzen, Humboldt-Universität zu Berlin, Chausseestrasse 117, 10115 Berlin, Germany.
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Wilde A, Fiedler B, Börner T. The cyanobacterial phytochrome Cph2 inhibits phototaxis towards blue light. Mol Microbiol 2002; 44:981-8. [PMID: 12010493 DOI: 10.1046/j.1365-2958.2002.02923.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We analysed the effects of inactivation of the phytochrome genes cph1 and cph2 on the phototactic migration of the cyanobacterium Synechocystis sp. PCC 6803 under different light qualities. Motility towards white, green, red and far red light was not altered in several independently raised cph1, cph2 and cph1/cph2 double mutants. Blue light (lambda = 400-500 nm) did not induce motility in wild-type and cph1 mutant cells, whereas cph2 and cph1/cph2 double mutants moved towards the blue light. Inhibition of the photosynthetic electron transport by DCMU influenced the motility of cph2 mutants under blue light, but not under white, red and far red light. RNA blot hybridizations did not indicate an altered transcript accumulation of the pilin-encoding pilA1 gene under blue light. We propose that the Cph2 protein is part of a light-stimulated signal transduction chain inhibiting the movement of Synechocystis sp. PCC 6803 cells towards blue light.
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Affiliation(s)
- Annegret Wilde
- Humboldt-Universität zu Berlin, Institut für Biologie, Chausseestr. 117, 10115 Berlin, Germany
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Büsch A, Friedrich B, Cramm R. Characterization of the norB gene, encoding nitric oxide reductase, in the nondenitrifying cyanobacterium Synechocystis sp. strain PCC6803. Appl Environ Microbiol 2002; 68:668-72. [PMID: 11823206 PMCID: PMC126718 DOI: 10.1128/aem.68.2.668-672.2002] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A norB gene encoding a putative nitric oxide reductase is present in the genome of the nondenitrifying cyanobacterium Synechocystis sp. strain PCC6803. The gene product belongs to the quinol-oxidizing single-subunit class of nitric oxide reductases, discovered recently in the denitrifier Ralstonia eutropha. Heterologous complementation of a nitric oxide reductase-negative mutant of R. eutropha with norB from Synechocystis restored nitric oxide reductase activity. With reduced menadione as the electron donor, an enzymatic activity of 101 nmol of NO per min per mg of protein was obtained with membrane fractions of Synechocystis wild-type cells. Virtually no nitric oxide reductase activity was present in a norB-negative mutant of Synechocystis. Growing cells of this mutant are more sensitive toward NO than wild-type cells, indicating that the presence of a nitric oxide reductase is beneficial for Synechocystis when the cells are exposed to NO. Transcriptional fusions with the chloramphenicol acetyltransferase reporter gene were constructed to monitor norB expression in Synechocystis. Transcription of norB was not enhanced by the addition of the NO-generating agent sodium nitroprusside.
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Affiliation(s)
- Andrea Büsch
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Chausseestrasse 117, D-10115 Berlin, Germany
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Wilde A, Churin Y, Schubert H, Börner T. Disruption of a Synechocystis sp. PCC 6803 gene with partial similarity to phytochrome genes alters growth under changing light qualities. FEBS Lett 1997; 406:89-92. [PMID: 9109392 DOI: 10.1016/s0014-5793(97)00248-2] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A gene that may encode a novel light sensing histidine protein kinase, designated plpA (phytochrome-like protein), was isolated from the cyanobacterium Synechocystis sp. PCC 6803. The 200 COOH-terminal amino acids of the gene product show homology with conserved domains of several bacterial histidine kinases and the ethylene response gene etr1 of Arabidopsis, whereas its central region is similar to the chromophore attachment site of plant phytochromes. Interruption or partial deletion of plpA yielded mutants unable to grow under blue light.
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Affiliation(s)
- A Wilde
- Institut für Biologie, Humboldt-Universität Berlin, Germany
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Wu J, Putnam-Evans C, Bricker TM. Site-directed mutagenesis of the CP 47 protein of photosystem II: 167W in the lumenally exposed loop C is required for photosystem II assembly and stability. PLANT MOLECULAR BIOLOGY 1996; 32:537-542. [PMID: 8980503 DOI: 10.1007/bf00019106] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The intrinsic chlorophyll-protein CP 47 is a component of photosystem II which functions in both light-harvesting and oxygen evolution. Using site-directed mutagenesis we have produced the mutant W167S which lies in loop C of CP 47. This strain exhibited a 75% loss in oxygen evolution activity and grew extremely slowly in the absence of glucose. Examination of normalized oxygen evolution traces indicated that the mutant was susceptible to photoinactivation. Analysis of the variable fluorescence yield indicated that the mutant accumulated very few functional PS II reaction centers. This was confirmed by immunoblotting experiments. Interestingly, when W167S was grown in the presence of 20 microM DCMU, the mutant continued to exhibit these defects. These results indicate that tryptophan 167 in loop C of CP 47 is important for the assembly and stability of the PS II reaction center.
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Affiliation(s)
- J Wu
- Department of Plant Biology, Louisiana State University, Baton Rouge 70803, USA
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14
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Shestakov S, Anbudurai P, Stanbekova G, Gadzhiev A, Lind L, Pakrasi H. Molecular cloning and characterization of the ctpA gene encoding a carboxyl-terminal processing protease. Analysis of a spontaneous photosystem II-deficient mutant strain of the cyanobacterium Synechocystis sp. PCC 6803. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)32175-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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