Low Activation State of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase in Carboxysome-Defective Synechococcus Mutants
- 1 May 1995
- journal article
- Published by Oxford University Press (OUP) in Plant Physiology
- Vol. 108 (1) , 183-190
- https://doi.org/10.1104/pp.108.1.183
Abstract
The high-CO2-requiring mutant of Synechococcus sp. PCC 7942, EK6, was obtained after extension of the C terminus of the small subunit of ribulose-1,5-bisphosphate (RuBP) carboxylase/oxygenase (Rubisco). The carboxysomes in EK6 were much larger than in the wild type, but the cellular distribution of the large and small sub-units of Rubisco was not affected. The kinetic parameters of in vitro-activated Rubisco were similar in EK6 and in the wild type. On the other hand, Rubisco appeared to be in a low state of activation in situ in EK6 cells pretreated with an air level of CO2. This was deduced from the appearance of a lag phase when carboxylation was followed with time in cells permeabilized by detergent and subsequently supplied with saturating CO2 and RuBP. Pretreatment of the cells with high CO2 virtually abolished the lag. After low-CO2 treatment, the internal RuBP pool was much higher in mutant cells than in the wild-type cells; pretreatment with high CO2 reduced the pool in mutant cells. We suggest that the high-CO2-requiring phenotype in mutants that possess aberrant carboxysomes arises from the inactivated state of Rubisco when the cells are exposed to low CO2.Keywords
This publication has 11 references indexed in Scilit:
- Inactivation of ccmO in Synechococcus sp. Strain PCC 7942 Results in a Mutant Requiring High Levels of CO(2).1994
- The X-ray structure of Synechococcus ribulose-bisphosphate carboxylase/oxygenase-activated quaternary complex at 2.2-A resolution.Journal of Biological Chemistry, 1993
- Analysis of a genomic DNA region from the cyanobacterium Synechococcus sp. strain PCC7942 involved in carboxysome assembly and functionJournal of Bacteriology, 1993
- Association of Carbonic Anhydrase Activity with Carboxysomes Isolated from the Cyanobacterium Synechococcus PCC7942Plant Physiology, 1992
- Mutations in the small subunit of ribulosebisphosphate carboxylase affect subunit binding and catalysisBiochemistry, 1991
- In situ assay of ribulose-1,5-bisphosphate carboxylase/oxygenase in Thiobacillus neapolitanusJournal of Bacteriology, 1991
- The 5'-flanking region of the gene encoding the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase is crucial for growth of the cyanobacterium Synechococcus sp. strain PCC 7942 at the level of CO2 in airJournal of Bacteriology, 1989
- Expression of Human Carbonic Anhydrase in the Cyanobacterium Synechococcus PCC7942 Creates a High CO2-Requiring PhenotypePlant Physiology, 1989
- Is There a Role for the 42 Kilodalton Polypeptide in Inorganic Carbon Uptake by Cyanobacteria?Plant Physiology, 1988
- Nature of the Inorganic Carbon Species Actively Taken Up by the Cyanobacterium Anabaena variabilisPlant Physiology, 1984