scholarly journals Learning RuBisCO's birth and subsequent environmental adaptation

2018 ◽  
Vol 47 (1) ◽  
pp. 179-185 ◽  
Author(s):  
Hiroki Ashida ◽  
Eiichi Mizohata ◽  
Akiho Yokota
Keyword(s):  
Co2 Fixation ◽  
Methanogenic Archaea ◽  
Environmental Adaptation ◽  
Bisphosphate Carboxylase ◽  
The Earth ◽  
Number Of Genes

Abstract It is believed that organisms that first appeared after the formation of the earth lived in a very limited environment, making full use of the limited number of genes. From these early organisms' genes, more were created by replication, mutation, recombination, translocation, and transmission of other organisms' DNA; thus, it became possible for ancient organisms to grow in various environments. The photosynthetic CO2-fixing enzyme RuBisCO (ribulose 1,5-bisphosphate carboxylase/oxygenase) began to function in primitive methanogenic archaea and has been evolved as a central CO2-fixing enzyme in response to the large changes in CO2 and O2 concentrations that occurred in the subsequent 4 billion years. In this review, the processes of its adaptation to be specialized for CO2 fixation will be presented from the viewpoint of functions and structures of RuBisCO.

Self-assembly in the carboxysome: a viral capsid-like protein shell in bacterial cells

2007 ◽  
Vol 35 (3) ◽  
pp. 508-511 ◽  
Author(s):  
T.O. Yeates ◽  
Y. Tsai ◽  
S. Tanaka ◽  
M.R. Sawaya ◽  
C.A. Kerfeld
Keyword(s):  
Self Assembly ◽  
Co2 Fixation ◽  
Closed Shell ◽  
Bacterial Cells ◽  
Protein Assemblies ◽  
Bisphosphate Carboxylase ◽  
Viral Capsids ◽  
Chemoautotrophic Bacteria ◽  
Assembly Principles ◽  
Protein Shell

Many proteins self-assemble to form large supramolecular complexes. Numerous examples of these structures have been characterized, ranging from spherical viruses to tubular protein assemblies. Some new kinds of supramolecular structures are just coming to light, while it is likely there are others that have not yet been discovered. The carboxysome is a subcellular structure that has been known for more than 40 years, but whose structural and functional details are just now emerging. This giant polyhedral body is constructed as a closed shell assembled from several thousand protein subunits. Within this protein shell, the carboxysome encapsulates the CO2-fixing enzymes, Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase) and carbonic anhydrase; this arrangement enhances the efficiency of cellular CO2 fixation. The carboxysome is present in many photosynthetic and chemoautotrophic bacteria, and so plays an important role in the global carbon cycle. It also serves as the prototypical member of what appears to be a large class of primitive protein-based organelles in bacteria. A series of crystal structures is beginning to reveal the secrets of how the carboxysome is assembled and how it enhances the efficiency of CO2 fixation. Some of the assembly principles revealed in the carboxysome are reminiscent of those seen in icosahedral viral capsids. In addition, the shell appears to be perforated by pores for metabolite transport into and out of the carboxysome, suggesting comparisons to the pores through oligomeric transmembrane proteins, which serve to transport small molecules across the membrane bilayers of cells and eukaryotic organelles.

CO2 refixation characteristics of developing canola seeds and silique wall

1998 ◽  
Vol 25 (3) ◽  
pp. 377 ◽  
Author(s):  
Steven P. King ◽  
Murray R. Badger ◽  
Robert T. Furbank
Keyword(s):  
Chlorophyll Content ◽  
Co2 Fixation ◽  
Incident Light ◽  
Critical Role ◽  
Photosynthetic Electron Transport ◽  
Total Activity ◽  
Brassica Napus L ◽  
Bisphosphate Carboxylase ◽  
Fixation Capacity

The potential for developing canola (Brassica napus L.) seeds and the interior silique (pod) wall to refix respired CO2 has been investigated. From ribulose-1,5-bisphosphate carboxylase–oxygenase (Rubisco) and phosphoenolpyruvate carboxylase (PEPC) activities, seeds were estimated to have a greater CO2 fixation capacity than silique wall endocarp during oil filling. The major component of seed fixation capacity was embryo Rubisco, which had a total activity of 6.3 nmol min-1 embryo-1 (3.7 µmol min-1 mg chlorophyll-1) at 28 days after anthesis (DAA) with smaller contributions from seed coat and embryo PEPC. Rubisco activities were probably maximal in vivo because of high silique cavity CO2 concentrations (0.8 to 2.5%). Seed chlorophyll content rapidly increased over 10-fold from 20 to 30 DAA and, with 20% of incident light transmitted through the silique wall, embryos demonstrated appreciable photosynthetic electron transport rates and most energy produced appeared to be used for Rubisco-catalysed CO2 fixation. Endocarp refixation capacity was less than seeds because chlorophyll content was not enriched and PEPC activities were relatively small. These data indicate that developing seeds and also endocarp refix respired CO2 and that embryo chlorophyll plays a critical role in this refixation.

Correlation Between the Development of Photorespiration and the Change in Activities of NH3 Assimilation Enzymes in Greening Oat Leaves

1991 ◽  
Vol 18 (6) ◽  
pp. 583 ◽  
Author(s):  
JW Yu ◽  
KC Woo
Keyword(s):  
Avena Sativa ◽  
Co2 Fixation ◽  
Chloroplast Development ◽  
Photosynthetic Capacity ◽  
Higher Plants ◽  
Glutamate Synthase ◽  
Chlorophyll Synthesis ◽  
Continuous Illumination ◽  
Bisphosphate Carboxylase ◽  
Glutamate Dehydrogenase Activity

The development of photosynthetic capacity and photorespiration during chloroplast development in 7-day-old etiolated oat (Avena sativa L.) primary leaves was investigated together with changes in the activity of possible NH3-assimilating enzymes. The development of photosynthetic CO2 fixation and photorespiration capacity, and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and glutamine synthetase (GS) activities comparable to green leaves were completed within 48 h of continuous illumination. Chlorophyll synthesis and glutamate synthase (GOGAT) activity continued to increase beyond this time. Within this 48-h period, the activities of Rubisco, GS and GOGAT increased 2.3, 2 and 3 times repectively. Throughout the greening treatment, the GS and GOGAT activities were always high enough to sustain the expected rate of photorespiratory NH3 production. In contrast, glutamate dehydrogenase activity decreased during greening, and its measured rate was not high enough for photorespirtory NH3 assimilation. These results support the idea that the GS/GOGAT pathway is the major, if not the only, route for photorespiratory NH3 assimilation in the light in leaves of higher plants.

scholarly journals Role of ClpP in the Biogenesis and Degradation of RuBisCO and ATP Synthase in Chlamydomonas reinhardtii

Plants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 191 ◽  
Author(s):  
Majeran ◽  
Wostrikoff ◽  
Wollman ◽  
Vallon
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Atp Synthase ◽  
Co2 Fixation ◽  
Inorganic Carbon ◽  
Point Mutations ◽  
Clp Protease ◽  
Bisphosphate Carboxylase ◽  
N Starvation ◽  
Sulfur Containing

Ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO) associates a chloroplast- and a nucleus-encoded subunit (LSU and SSU). It constitutes the major entry point of inorganic carbon into the biosphere as it catalyzes photosynthetic CO2 fixation. Its abundance and richness in sulfur-containing amino acids make it a prime source of N and S during nutrient starvation, when photosynthesis is downregulated and a high RuBisCO level is no longer needed. Here we show that translational attenuation of ClpP1 in the green alga Chlamydomonas reinhardtii results in retarded degradation of RuBisCO during S- and N-starvation, suggesting that the Clp protease is a major effector of RubisCO degradation in these conditions. Furthermore, we show that ClpP cannot be attenuated in the context of rbcL point mutations that prevent LSU folding. The mutant LSU remains in interaction with the chloroplast chaperonin complex. We propose that degradation of the mutant LSU by the Clp protease is necessary to prevent poisoning of the chaperonin. In the total absence of LSU, attenuation of ClpP leads to a dramatic stabilization of unassembled SSU, indicating that Clp is responsible for its degradation. In contrast, attenuation of ClpP in the absence of SSU does not lead to overaccumulation of LSU, whose translation is controlled by assembly. Altogether, these results point to RuBisCO degradation as one of the major house-keeping functions of the essential Clp protease. In addition, we show that non-assembled subunits of the ATP synthase are also stabilized when ClpP is attenuated. In the case of the atpA-FUD16 mutation, this can even allow the assembly of a small amount of CF1, which partially restores phototrophy.

Regulation of CO2 Fixation by the Ribulose 1,5-Bisphosphate Carboxylase in the Chloroplast

1987 ◽  
pp. 273-279
Author(s):  
R. G. Jensen ◽  
D. A. Raynes ◽  
R. E. B. Seftor ◽  
S. W. gustafson
Keyword(s):  
Co2 Fixation ◽  
Bisphosphate Carboxylase
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