Herbicide Resistance and Supersensitivity in Ala250 or Ala251 Mutants of the D1 Protein in Chlamydomonas reinhardtii

Johanningmeier, Udo; Sopp, Gabriele; Brauner, Marco; Altenfeld, Ursula; Orawski, Grazyna; Oettmeier, Walter

doi:10.1006/pest.1999.2455

Cited by 25 publications

(15 citation statements)

References 33 publications

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“…Most of these mutations were localised in the D1 primary structure encompassing amino acids from phenylalanine 211 to leucine 275 [12], [22], [33], [34]. In C. reinhardtii , it has been demonstrated that aminoacidic mutations outside this region can also modify the herbicide sensitivity, leading to hypothesise long-range effects in the arrangement of the D1 Q B hosting cavity [22].…”

Section: Resultsmentioning

confidence: 99%

A Powerful Molecular Engineering Tool Provided Efficient Chlamydomonas Mutants as Bio-Sensing Elements for Herbicides Detection

et al. 2013

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This study was prompted by increasing concerns about ecological damage and human health threats derived by persistent contamination of water and soil with herbicides, and emerging of bio-sensing technology as powerful, fast and efficient tool for the identification of such hazards. This work is aimed at overcoming principal limitations negatively affecting the whole-cell-based biosensors performance due to inadequate stability and sensitivity of the bio-recognition element. The novel bio-sensing elements for the detection of herbicides were generated exploiting the power of molecular engineering in order to improve the performance of photosynthetic complexes. The new phenotypes were produced by an in vitro directed evolution strategy targeted at the photosystem II (PSII) D1 protein of Chlamydomonas reinhardtii, using exposures to radical-generating ionizing radiation as selection pressure. These tools proved successful to identify D1 mutations conferring enhanced stability, tolerance to free-radical-associated stress and competence for herbicide perception. Long-term stability tests of PSII performance revealed the mutants capability to deal with oxidative stress-related conditions. Furthermore, dose-response experiments indicated the strains having increased sensitivity or resistance to triazine and urea type herbicides with I50 values ranging from 6×10−8 M to 2×10−6 M. Besides stressing the relevance of several amino acids for PSII photochemistry and herbicide sensing, the possibility to improve the specificity of whole-cell-based biosensors, via coupling herbicide-sensitive with herbicide-resistant strains, was verified.

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Section: Resultsmentioning

confidence: 99%

A Powerful Molecular Engineering Tool Provided Efficient Chlamydomonas Mutants as Bio-Sensing Elements for Herbicides Detection

et al. 2013

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“…Among them, 27 mutations consisted of Ser264 replacement, a finding in agreement with the well accepted concept that this aminoacid is the principal binding target of triazines and urea type herbicides. Other frequently cited aminoacid substitutions resulting in changes in the atrazine/D1 interaction are localized on Ala at positions 250 and 251, 8 and 9 mutations, respectively (Oettmeier 1999;Johanningmeier et al, 2000). The increasing number of data coming from atrazine resistant/sensitive mutants and the advances in the computation of structure design and modelling could significantly expand our knowledge on herbicide and PSII reaction centre interactions ).…”

Section: Atrazine: a Case Study Exploitation And Mode Of Actionmentioning

confidence: 99%

“…Analysis of mutations conferring herbicide resistance or sensitivity indicated that Ala 250, Ala251 and Ser264 are located close to the atrazine binding pocket and probably directly interact with it (see above, Oettmeier 1999;Johanningmeier et al, 2000). Using this information, in the previous study cited above we obtained a molecular view of the atrazine-D1 interactions using a combination of molecular docking and energy minimization techniques .…”

Section: Molecular Dynamics Simulations Of Psii-atrazine Complex Relmentioning

confidence: 99%

Computational Biology, Protein Engineering, and Biosensor Technology: a Close Cooperation for Herbicides Monitoring

Rea¹,

Polticelli²,

Antonacci³

et al. 2011

Herbicides, Theory and Applications

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“…Its derivative Del1 mutant carrying a defined deletion in the psbA gene, was used as a recipient strain to obtain D1 site-directed mutants by particle gun transformation. 24 Site-directed mutagenesis and chloroplast transformation procedures Site-directed mutagenesis of the psbA gene encoding the D1 protein was performed as previously described 37,38 by PCR using the mutagenic primers:…”

Section: Strains and Culture Conditionsmentioning

confidence: 99%

Structure‐based design of novel Chlamydomonas reinhardtii D1‐D2 photosynthetic proteins for herbicide monitoring

et al. 2009

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The D1-D2 heterodimer in the reaction center core of phototrophs binds the redox plastoquinone cofactors, Q A and Q B , the terminal acceptors of the photosynthetic electron transfer chain in the photosystem II (PSII). This complex is the target of the herbicide atrazine, an environmental pollutant competitive inhibitor of Q B binding, and consequently it represents an excellent biomediator to develop biosensors for pollutant monitoring in ecosystems. In this context, we have undertaken a study of the Chlamydomonas reinhardtii D1-D2 proteins aimed at designing site directed mutants with increased affinity for atrazine. The three-dimensional structure of the D1 and D2 proteins from C. reinhardtii has been homology modeled using the crystal structure of the highly homologous Thermosynechococcus elongatus proteins as templates. Mutants of D1 and D2 were then generated in silico and the atrazine binding affinity of the mutant proteins has been calculated to predict mutations able to increase PSII affinity for atrazine. The computational approach has been validated through comparison with available experimental data and production and characterization of one of the predicted mutants. The latter analyses indicated an increase of one order of magnitude of the mutant sensitivity and affinity for atrazine as compared to the control strain. Finally, D1-D2 heterodimer mutants were designed and selected which, according to our model, increase atrazine binding affinity by up to 20 kcal/mol, representing useful starting points for the development of high affinity biosensors for atrazine.

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Herbicide Resistance and Supersensitivity in Ala250 or Ala251 Mutants of the D1 Protein in Chlamydomonas reinhardtii

Cited by 25 publications

References 33 publications

A Powerful Molecular Engineering Tool Provided Efficient Chlamydomonas Mutants as Bio-Sensing Elements for Herbicides Detection

A Powerful Molecular Engineering Tool Provided Efficient Chlamydomonas Mutants as Bio-Sensing Elements for Herbicides Detection

Computational Biology, Protein Engineering, and Biosensor Technology: a Close Cooperation for Herbicides Monitoring

Structure‐based design of novel Chlamydomonas reinhardtii D1‐D2 photosynthetic proteins for herbicide monitoring

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