Abstract
The distribution of phosphoribulose kinase (PRK) in the cyanelles of Cyanophora paradoxa Korschikoff and Glaucocystis nostochinearum Itzigsohn was studied by protein A-gold immunoelectron microscopy. In both endocyanomes, antiserum against PRK heavily labeled the thylakoid region of the cyanelles, whereas little or no label was present over the carboxysomes. Antiserum against ribulose 1,5-bisphosphate carboxylase/oxygenase by contrast heavily labeled the carboxysomes of each endocyanome. In vitro studies of PRK distribution in cell-free extracts of C. paradoxa showed that 93% of the enzyme was in the soluble fraction. Quantitative immunoelectron microscopy showed that more than 99% of the PRK in the cyanelle of C. paradoxa was localized in the thylakoid region. We conclude that the carboxysomes of cyanelles like the carboxysomes of autotrophic prokaryotes and the pyrenoids of green algal chloroplasts do not contain phosphoribulose kinase.
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- Holdsworth R. H. The isolation and partial characterization of the pyrenoid protein of Eremosphaera viridis. J Cell Biol. 1971 Nov;51(21):499–513. doi: 10.1083/jcb.51.2.499. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lacoste-Royal G., Gibbs S. P. Ochromonas mitochondria contain a specific chloroplast protein. Proc Natl Acad Sci U S A. 1985 Mar;82(5):1456–1459. doi: 10.1073/pnas.82.5.1456. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shively J. M. Inclusion bodies of prokaryotes. Annu Rev Microbiol. 1974;28(0):167–187. doi: 10.1146/annurev.mi.28.100174.001123. [DOI] [PubMed] [Google Scholar]