Amplification of maize ribulose bisphosphate carboxylase large subunit synthesis in E. coli by transcriptional fusion with the lambda N operon

1982 ◽  
Vol 185 (3) ◽  
pp. 424-429 ◽  
Author(s):  
A. A. Gatenby ◽  
J. A. Castleton
Keyword(s):  
Large Subunit ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Transcriptional Fusion ◽  
Bisphosphate Carboxylase ◽  
E Coli

The CO2/O2 specificity of single-subunit ribulose-bisphosphate carboxylase from the dinoflagellate, Amphidinium carterae

1998 ◽  
Vol 25 (2) ◽  
pp. 131 ◽  
Author(s):  
Spencer M. Whitney ◽  
T. John Andrews
Keyword(s):  
Large Subunit ◽  
Anaerobic Bacteria ◽  
Carbon Gain ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Amphidinium Carterae ◽  
Bisphosphate Carboxylase ◽  
Cell Extracts ◽  
Ribulose Bisphosphate Carboxylase Oxygenase ◽  
Alternate Substrate

Some dinoflagellates have been shown recently to be unique among eukaryotes in having a ribulose-bisphosphate carboxylase-oxygenase (Rubisco, EC 4.1.1.39) composed of only one type of subunit, the 53-kDa large subunit [reviewed by Palmer, J.D. (1996) Plant Cell 8, 343–345]. Formerly, such homomeric Rubiscos had been found only in anaerobic bacteria and are characterised by such poor abilities to discriminate against the competitive alternate substrate, O2, that they would not be able to support net carbon gain if exposed to the current atmospheric CO2/O2 ratio. The capacity of Rubiscos from aerobic organisms to discriminate more effectively against O2 appeared to correlate with the presence of additional 12- to 18-kDa small subunits. Thus the CO2/O2 specificity of the homomeric dinoflagellate Rubisco is of considerable interest from the structural, physiological and evolutionary viewpoints. However, for unknown reasons, Rubiscos from dinoflagellates studied so far are so unstable after extraction from the cells that kinetic characterisation has not been possible. We redesigned two methods for measuring Rubisco’s CO2/O2 specificity to adapt them to rapid measurement at 10°C using unfractionated cell extracts. Both methods revealed that the CO2/O2 specificity of Rubisco from the dinoflagellate, Amphidinium carterae Hulburt, was approximately twice as great as that of other homomeric Rubiscos but unlikely to be sufficient to support dinoflagellate photosynthesis without assistance from an inorganic-carbon-concentrating mechanism.

Photoregulation of the biosynthesis of ribulose bisphosphate carboxylase

Development ◽  
1984 ◽  
Vol 83 (Supplement) ◽  
pp. 163-178
Author(s):  
R. John Ellis ◽  
Thomas F. Gallagher ◽  
Gareth I. Jenkins ◽  
C. Ruth Lennox
Keyword(s):  
Chloroplast Development ◽  
Higher Plants ◽  
Large Subunit ◽  
Nuclear Genome ◽  
Small Subunit ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Bisphosphate Carboxylase ◽  
Subunit Mrna ◽  
Parallel Increase

Chloroplast development in higher plants is light dependent, and is accompanied by the synthesis of chlorophyll and the accumulation of many chloroplast polypeptides. There is a 100-fold greater content of the photosynthetic enzyme, ribulose-1,5-bisphosphate carboxylase-oxygenase, in light-grown seedlings of Pisum sativum than in dark-grown seedlings. Following the illumination of dark-grown seedlings, there is a parallel increase in the content of both the mRNA and the polypeptide of the small subunit of the carboxylase; this subunit is a product of the nuclear genome. The increases in the mRNA and the polypeptide of the large subunit, which is a product of the chloroplast genome, show less synchronicity. Studies with isolated leaf nuclei show that the increase in small subunit mRNA is mediated primarily at the level of transcription. Three distinct effects of light on transcription of small subunit genes have been found; a rapid (∼1 h) burst, followed by a decline, when etiolated plants are first exposed to light; a slow (∼36h) development of the competence to transcribe rapidly after the initial burst; rapid (∼20 min) switches in both directions when fully greened plants are exposed to light—dark transitions.

Sign in / Sign up

Export Citation Format

Share Document