scholarly journals Probing the rice Rubisco–Rubisco activase interaction via subunit heterooligomerization

2019 ◽  
Vol 116 (48) ◽  
pp. 24041-24048 ◽  
Author(s):  
Devendra Shivhare ◽  
Jediael Ng ◽  
Yi-Chin Candace Tsai ◽  
Oliver Mueller-Cajar
Keyword(s):  
Active Sites ◽  
Crop Improvement ◽  
Fold Increase ◽  
Rubisco Activase ◽  
Growth And Yield ◽  
Higher Plant ◽  
Bisphosphate Carboxylase ◽  
Functional Understanding ◽  
Sugar Phosphates ◽  
Aaa Protein

During photosynthesis the AAA+ protein and essential molecular chaperone Rubisco activase (Rca) constantly remodels inhibited active sites of the CO2-fixing enzyme Rubisco (ribulose 1,5-bisphosphate carboxylase/oxygenase) to release tightly bound sugar phosphates. Higher plant Rca is a crop improvement target, but its mechanism remains poorly understood. Here we used structure-guided mutagenesis to probe the Rubisco-interacting surface of rice Rca. Mutations in Ser-23, Lys-148, and Arg-321 uncoupled adenosine triphosphatase and Rca activity, implicating them in the Rubisco interaction. Mutant doping experiments were used to evaluate a suite of known Rubisco-interacting residues for relative importance in the context of the functional hexamer. Hexamers containing some subunits that lack the Rubisco-interacting N-terminal domain displayed a ∼2-fold increase in Rca function. Overall Rubisco-interacting residues located toward the rim of the hexamer were found to be less critical to Rca function than those positioned toward the axial pore. Rca is a key regulator of the rate-limiting CO2-fixing reactions of photosynthesis. A detailed functional understanding will assist the ongoing endeavors to enhance crop CO2 assimilation rate, growth, and yield.

scholarly journals Rubisco activase requires residues in the large subunit N terminus to remodel inhibited plant Rubisco

2020 ◽  
Vol 295 (48) ◽  
pp. 16427-16435
Author(s):  
Jediael Ng ◽  
Zhijun Guo ◽  
Oliver Mueller-Cajar
Keyword(s):  
Higher Plants ◽  
Large Subunit ◽  
Rubisco Activase ◽  
Higher Plant ◽  
Bisphosphate Carboxylase ◽  
Interaction Sites ◽  
Dead End ◽  
Highly Sensitive ◽  
N Terminus ◽  
Sugar Phosphates

The photosynthetic CO2 fixing enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) forms dead-end inhibited complexes while binding multiple sugar phosphates, including its substrate ribulose 1,5-bisphosphate. Rubisco can be rescued from this inhibited form by molecular chaperones belonging to the ATPases associated with diverse cellular activities (AAA+ proteins) termed Rubisco activases (Rcas). The mechanism of green-type Rca found in higher plants has proved elusive, in part because until recently higher-plant Rubiscos could not be expressed recombinantly. Identifying the interaction sites between Rubisco and Rca is critical to formulate mechanistic hypotheses. Toward that end here we purify and characterize a suite of 33 Arabidopsis Rubisco mutants for their ability to be activated by Rca. Mutation of 17 surface-exposed large subunit residues did not yield variants that were perturbed in their interaction with Rca. In contrast, we find that Rca activity is highly sensitive to truncations and mutations in the conserved N terminus of the Rubisco large subunit. Large subunits lacking residues 1–4 are functional Rubiscos but cannot be activated. Both T5A and T7A substitutions result in functional carboxylases that are poorly activated by Rca, indicating the side chains of these residues form a critical interaction with the chaperone. Many other AAA+ proteins function by threading macromolecules through a central pore of a disc-shaped hexamer. Our results are consistent with a model in which Rca transiently threads the Rubisco large subunit N terminus through the axial pore of the AAA+ hexamer.

scholarly journals Insights into the mechanism and regulation of the CbbQO-type Rubisco activase, a MoxR AAA+ ATPase

2019 ◽  
Vol 117 (1) ◽  
pp. 381-387 ◽  
Author(s):  
Yi-Chin Candace Tsai ◽  
Fuzhou Ye ◽  
Lynette Liew ◽  
Di Liu ◽  
Shashi Bhushan ◽  
...  
Keyword(s):  
Active Sites ◽  
Adaptor Protein ◽  
Rubisco Activase ◽  
Site Directed Mutagenesis ◽  
Successful Implementation ◽  
Bisphosphate Carboxylase ◽  
Aaa Atpase ◽  
Negative Stain ◽  
Sugar Phosphates ◽  
Chemoautotrophic Bacteria

The vast majority of biological carbon dioxide fixation relies on the function of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco). In most cases the enzyme exhibits a tendency to become inhibited by its substrate RuBP and other sugar phosphates. The inhibition is counteracted by diverse molecular chaperones known as Rubisco activases (Rcas). In some chemoautotrophic bacteria, the CbbQO-type Rca Q2O2 repairs inhibited active sites of hexameric form II Rubisco. The 2.2-Å crystal structure of the MoxR AAA+ protein CbbQ2 fromAcidithiobacillus ferrooxidansreveals the helix 2 insert (H2I) that is critical for Rca function and forms the axial pore of the CbbQ hexamer. Negative-stain electron microscopy shows that the essential CbbO adaptor protein binds to the conserved, concave side of the CbbQ2 hexamer. Site-directed mutagenesis supports a model in which adenosine 5′-triphosphate (ATP)-powered movements of the H2I are transmitted to CbbO via the concave residue L85. The basal ATPase activity of Q2O2 Rca is repressed but strongly stimulated by inhibited Rubisco. The characterization of multiple variants where this repression is released indicates that binding of inhibited Rubisco to the C-terminal CbbO VWA domain initiates a signal toward the CbbQ active site that is propagated via elements that include the CbbQ α4-β4 loop, pore loop 1, and the presensor 1-β hairpin (PS1-βH). Detailed mechanistic insights into the enzyme repair chaperones of the highly diverse CO2fixation machinery of Proteobacteria will facilitate their successful implementation in synthetic biology ventures.

scholarly journals Rubisco activase remodels plant Rubisco via the large subunit N-terminus

2020 ◽  
Author(s):  
Jediael Ng ◽  
Oliver Mueller-Cajar
Keyword(s):  
Higher Plants ◽  
Large Subunit ◽  
Rubisco Activase ◽  
Higher Plant ◽  
Bisphosphate Carboxylase ◽  
Interaction Sites ◽  
Highly Sensitive ◽  
N Terminus ◽  
Sugar Phosphates

ABSTRACTThe photosynthetic CO2 fixing enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) forms inhibited complexes with multiple sugar phosphates, including its substrate ribulose 1,5-bisphosphate. At least three classes of ATPases associated with diverse cellular activities (AAA+ proteins) termed Rubisco activases (Rcas) have evolved to remodel inhibited Rubisco complexes. The mechanism of green-type Rca found in higher plants has proved elusive, because until recently higher plant Rubiscos could not be expressed recombinantly. Towards identifying interaction sites between Rubisco and Rca, here we produce and characterize a suite of 33 Arabidopsis Rubisco mutants for their ability to be activated by Rca. We find that Rca activity is highly sensitive to truncations and mutations in the conserved N-terminus of the Rubisco large subunit. Both T5A and T7A substitutions cannot be activated by Rca, but present with increased carboxylation velocities. Our results are consistent with a model where Rca functions by transiently threading the Rubisco large subunit N-terminus through the axial pore of the AAA+ hexamer.

Structure ofArabidopsis thalianaRubisco activase

2015 ◽  
Vol 71 (4) ◽  
pp. 800-808 ◽  
Author(s):  
Dirk Hasse ◽  
Anna M. Larsson ◽  
Inger Andersson
Keyword(s):  
Conformational Changes ◽  
Rubisco Activase ◽  
Sulfate Ion ◽  
Bisphosphate Carboxylase ◽  
Sulfate Ions ◽  
Dead End ◽  
Inhibitory Compounds ◽  
Density Map ◽  
Sugar Phosphates ◽  
Electron Density Map

The CO2-fixing enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is inactivated by the formation of dead-end complexes with inhibitory sugar phosphates. In plants and green algae, the ATP-dependent motor protein Rubisco activase restores catalytic competence by facilitating conformational changes in Rubisco that promote the release of the inhibitory compounds from the active site. Here, the crystal structure of Rubisco activase fromArabidopsis thalianais presented at 2.9 Å resolution. The structure reveals an AAA+ two-domain structure. More than 100 residues in the protein were not visible in the electron-density map owing to conformational disorder, but were verified to be present in the crystal by mass spectrometry. Two sulfate ions were found in the structure. One was bound in the loop formed by the Walker A motif at the interface of the domains. A second sulfate ion was bound at the N-terminal end of the first helix of the C-terminal domain. The protein packs in a helical fashion in the crystal, as observed previously for Rubisco activase, but differences in the helical pitch indicate flexibility in the packing of the protein.

Immunolocalization of Rubisco Activase and Rubisco in C3 and C4 Plant Tissues

2000 ◽  
Vol 6 (S2) ◽  
pp. 472-473
Author(s):  
S. Madhavan ◽  
M. S. Miller-Goodman ◽  
K. W. Lee
Keyword(s):  
Higher Plants ◽  
Tight Binding ◽  
Rubisco Activase ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate Carboxylase Oxygenase ◽  
Microscopic Studies ◽  
Sugar Phosphates

Ribulose bisphosphate carboxylase/oxygenase (Rubisco), an abundant enzyme in chloroplasts, must be activated by CO2 in order for it to catalyze the carboxylation of ribulose bisphosphate. Rubisco activase, a nuclear encoded chloroplast protein was first identified as a biochemical lesion in the rca mutant of Arabidopsis (1) which lacked this enzyme. Study of Rubisco in this mutant (2) and transgenic tobacco plants with reduced Rubisco activase levels showed that Rubisco could not achieve and maintain an adequate level of activity, in vivo, without an activase. Rubisco activase promotes ‘activation’ of Rubisco by overcoming the deleterious effects of tight binding sugar phosphates and low chloroplast CO2 levels on catalysis and carbamylation (1).Rubisco activase has been detected in higher plants (3), in unicellular green algae (4,5) and in cyanobacteria (6). Though the presence of Rubisco in guard cell chlroplasts was a subject of controversy, several immunolight and immunoelectron microscopic studies have demonstrated the presence of Rubisco in guard cells (7).

scholarly journals The Catalytic Role of RuBisCO for in situ CO2 Recycling in Escherichia coli

2020 ◽  
Vol 8 ◽  
Author(s):  
Ju-Jiun Pang ◽  
Jong-Shik Shin ◽  
Si-Yu Li
Keyword(s):  
Escherichia Coli ◽  
Rubisco Activase ◽  
Bisphosphate Carboxylase ◽  
Metabolite Production ◽  
E Coli ◽  
Theoretical Yield ◽  
Key Enzyme ◽  
Sugar Phosphates

Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) is a key enzyme responsible for biological CO2 assimilation. RuBisCO can be heterologously expressed in Escherichia coli so that glucose and CO2 are co-metabolized to achieve high mixotrophic metabolite production, where the theoretical yield of mixotrophic metabolite production is 2.4 mol(ethanol+acetate+pyruvate)/molglucose. However, RuBisCO is known for its low kcat and for forming inhibited complexes with its substrate ribulose-1,5-bisphosphate (RuBP) and other sugar phosphates, yet the inhibited form of RuBisCO can be reversed by RuBisCO activase (Rca). In this study, RuBisCO forms I and II were cloned and expressed in Escherichia coli for in situ CO2 recycling, where CO2 produced during glucose fermentation was recycled and co-metabolized with the glucose. In addition, forms I and II RuBisCO activases were co-expressed with RuBisCO in E. coli to determine their in vivo effects on in situ CO2 recycling. Form I RuBisCO activase (Rca1) was co-expressed with form I RuBisCO and form II RuBisCO activase (Rca2) was co-expressed with form II RuBisCO. The results showed that both form I and form II RuBisCO exhibit comparable activities in E. coli and generated similar levels of in situ CO2 recycling. A significant increase in the total metabolite yield from 1.5 ± 0.1 to 2.2 ± 0.1 mol(ethanol+acetate+pyruvate)/molglucose occurred when Rca2 was co-expressed with form II RuBisCO. Meanwhile, the total metabolite yield increased from 1.7 ± 0.1 to 2.0 ± 0.1 mol(ethanol+acetate+pyruvate)/molglucose when Rca1 was co-expressed with form I RuBisCO. This data suggests that both forms I and II RuBisCO are subject to in vivo RuBP inhibition yet can be relieved by the co-expression of Rca. Interestingly, it is suggested that the in vivo RuBP inhibition of form II RuBisCO can be more easily reversed compared to form I. When the catalytic power of RuBisCO is maintained by Rca, the high activity of phosphoribulokinase (Prk) plays an important role in directing glucose to the RuBisCO-based engineered pathway and fermentation yields of 2.1–2.3 mol(ethanol+acetate+pyruvate)/molglucose can be obtained. This study is the first to demonstrate that in vivo RuBP inhibition of RuBisCO can be a bottleneck for in situ CO2 recycling in E. coli.

scholarly journals Atomic Resolution X-ray Structure of the Substrate Recognition Domain of Higher Plant Ribulose-bisphosphate Carboxylase/Oxygenase (Rubisco) Activase

2011 ◽  
Vol 286 (41) ◽  
pp. 35683-35688 ◽  
Author(s):  
J. Nathan Henderson ◽  
Agnieszka M. Kuriata ◽  
Raimund Fromme ◽  
Michael E. Salvucci ◽  
Rebekka M. Wachter
Keyword(s):  
Mechanical Energy ◽  
Tight Binding ◽  
Rubisco Activase ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Higher Plant ◽  
Bisphosphate Carboxylase ◽  
Aaa Atpase ◽  
Ribulose Bisphosphate Carboxylase Oxygenase ◽  
Species Specific

The rapid release of tight-binding inhibitors from dead-end ribulose-bisphosphate carboxylase/oxygenase (Rubisco) complexes requires the activity of Rubisco activase, an AAA+ ATPase that utilizes chemo-mechanical energy to catalyze the reactivation of Rubisco. Activase is thought to play a central role in coordinating the rate of CO2 fixation with the light reactions of photosynthesis. Here, we present a 1.9 Å crystal structure of the C-domain core of creosote activase. The fold consists of a canonical four-helix bundle, from which a paddle-like extension protrudes that entails a nine-turn helix lined by an irregularly structured peptide strand. The residues Lys-313 and Val-316 involved in the species-specific recognition of Rubisco are located near the tip of the paddle. An ionic bond between Lys-313 and Glu-309 appears to stabilize the glycine-rich end of the helix. Structural superpositions onto the distant homolog FtsH imply that the paddles extend away from the hexameric toroid in a fan-like fashion, such that the hydrophobic sides of each blade bearing Trp-302 are facing inward and the polar sides bearing Lys-313 and Val-316 are facing outward. Therefore, we speculate that upon binding, the activase paddles embrace the Rubisco cylinder by placing their hydrophobic patches near the partner protein. This model suggests that conformational adjustments at the remote end of the paddle may relate to selectivity in recognition, rather than specific ionic contacts involving Lys-313. Additionally, the superpositions predict that the catalytically critical Arg-293 does not interact with the bound nucleotide. Hypothetical ring-ring stacking and peptide threading models for Rubisco reactivation are briefly discussed.

scholarly journals Effects of selenium (Se) application and arbuscular mycorrhizal (AMF) inoculation on soybean (Glycine max) and forage grass (Urochloa decumbens) development in oxisol

2019 ◽  
Vol 13 ((03) 2019) ◽  
pp. 380-385 ◽  
Author(s):  
Soraya Marx Bamberg ◽  
Silvio Junio Ramos ◽  
Marco Aurelio Carbone Carneiro ◽  
José Oswaldo Siqueira
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Fold Increase ◽  
Tropical Soils ◽  
Fertilizer Application ◽  
Growth And Yield ◽  
Forage Grass ◽  
Urochloa Decumbens ◽  
Soybean Plants ◽  
Amf Inoculation

Fertilizer application can enhance the nutritional value of plants, such effects being influenced by the presence of arbuscular mycorrhizal fungi (AMF). Nutrients × AMF interactions are well-known for variety of elements but very little has been addressed on biofortification of selenium (Se) in plants grown in tropical soils. The purpose of this study was to evaluate the effect of Se application and AMF inoculation on growth and micronutrient contents on soybean plants as forage grass. The experiments were conducted in a completely randomized factorial design with five Se doses (0.0, 0.5, 1.0, 2.0 and 3.0 mg kg-1 for soybean plants, and 0.0, 0.5, 1.0, 3.0 and 6.0 mg kg-1 for forage plants), with and without AMF inoculation in three replicates. The results showed that soil Se had only slight effect on soybean growth but it caused a two-fold increase on grain yield. However, the growth of forage grass was enhanced by Se application when AMF was present. The AMF inoculation reduced benefit for soybean growth and yield but marked positive effect on forage grass at high doses of Se. Selenium contents in both plants were increased by its application in soil, being such effect proportional to soil applied doses. Selenium application and AMF inoculation had marked effects on micronutrients contents in both soybean plants and forage grass and they may contribute to Se and micronutrient biofortification.

Physiological attributes of mungbean (Vigna radiata L.) influenced by different sources of nutrients (NPK) in Madhupur tract region of Bangladesh

2021 ◽  
Vol 11 (01) ◽  
pp. 736-748
Author(s):  
M. M. Hossain ◽  
◽  
S. Yesmin ◽  
M. Z. Islam ◽  
M. A. Hossain ◽  
...  
Keyword(s):  
Plant Growth ◽  
Seed Yield ◽  
Block Design ◽  
Growth And Yield ◽  
Higher Plant ◽  
Npk Fertilizers ◽  
Straw Yield ◽  
Combined Application ◽  
Randomized Complete Block Design ◽  
Different Sources

An experiment was conducted at the Sher-e-Bangla Agricultural University farm from April to June 2017 in Kharif season to evaluate the performance of two mungbean varieties under different NPK fertilizers doses in field conditions. The experiment was laid out in Randomized Complete Block Design (RCBD), comprising six treatments with three replications. In the experiment, varieties used were BARI mung-6 and BARI mung-5 and the combination of the treatment were T0 = (control), T1 (10-40-25 NPK kg ha-1), T2 (10-60-45 NPK kg ha-1), T3 (20-50-35 NPK kg ha-1), T4 (30-40-25 NPK kg ha-1) and T5 (30-40-45 NPK kg ha-1), respectively. Mungbean cultivars responded noticeably to the supplementary NPK fertilizers as the crop characters were significantly influenced by different levels of NPK fertilizers. Data were recorded on plant height, leaves plant-1, branches plant-1, pods plant-1, seeds pod-1, 1000-seed weight, seed, and straw yield at different days after sowing. Of the two varieties, BARI mung-6 gave the highest seed yield (1.72 t ha-1) next to the higher plant growth and straw yield On the contrary, BARI mung-5 cultivar produced the lowest seed yield (1.57t ha-1), plant growth, and straw yield. The results showed that T3 (20-50-35 NPK kg ha-1) treatment was the best treatment as regards plant growth and yield parameters. The highest seed yield was produced by treated plot T3 (20-50-35 NPK kg ha-1) over the untreated control plot, T1, T2, T4, and T5, respectively. As for the combined effect, V1T3 (BARI mung-6 and T3 = 20kg N + 50kg P + 35kg K ha-1) performed the best results in all growth and development characters. Therefore, the combined application of 20-50-35 kg NPK ha-1 might be considered to be found optimal to get a considerable seed yield of mungbean variety BARI mung-6.

Sign in / Sign up

Export Citation Format

Share Document