Fraction of pyrenoid's protein that is RuBisCO

Range >90 %
Organism Algae Eremosphaera viridis
Reference Engel, B. D., Schaffer, M., Kuhn Cuellar, L., Villa, E., Plitzko, J. M., and Baumeister, W. (2015). Native architecture of the Chlamydomonas chloroplast revealed by in situ cryo-electron tomography. Elife 4, 1–29. p.10 2nd paragraphPubMed ID25584625
Primary Source Holdsworth RH. 1971. The isolation and partial characterization of the pyrenoid protein of Eremosphaera viridis. The Journal of Cell Biology 51 :499–513. doi: 10.1083/jcb.51.2.499.PubMed ID5112653
Method (Primary source abstract:) The pyrenoids of Eremosphaera viridis, a green alga, were isolated by density gradient centrifugation and their physical and enzymatic properties were studied. The ultraviolet absorption spectrum of sodium dodecyl sulfate (SDS) extracts of pyrenoids showed a single peak at a wavelength of 277 nm, indicating the presence of protein and the probable absence of nucleic acid. Upon electrophoresis on polyacrylamide gels containing SDS, 16 bands were resolved of which two, together, accounted for 90% of the total protein on the gels."
Comments "RuBisCO accounts for over 90% of the pyrenoid's protein content (primary source). Such homogeneity suggests that the pyrenoid may exhibit higher-order organization, and indeed, ‘crystalline’ packing of RuBisCO complexes has been described in a few algal pyrenoids (Holdsworth, 1968 Kowallik, 1969) as well as bacterial carboxysomes (Schmid et al., 2006 Iancu et al., 2007)."
Entered by Uri M
ID 111332