caa a22 4500 445889551 CHVBK 20180317145611.0 cr unu---uuuuu 170323e20110901xx s 000 0 eng 10.1007/s11120-011-9659-8 doi (NATIONALLICENCE)springer-10.1007/s11120-011-9659-8 Over-expression of the β-carboxysomal CcmM protein in Synechococcus PCC7942 reveals a tight co-regulation of carboxysomal carbonic anhydrase (CcaA) and M58 content [Elektronische Daten] [Benedict Long, Benjamin Rae, Murray Badger, G. Dean Price] Carboxysomes, containing the cell's complement of RuBisCO surrounded by a specialized protein shell, are a central component of the cyanobacterial CO2-concentrating mechanism. The ratio of two forms of the β-carboxysomal protein CcmM (M58 and M35) may affect the carboxysomal carbonic anhydrase (CcaA) content. We have over-expressed both M35 and M58 in the β-cyanobacterium Synechococcus PCC7942. Over-expression of M58 resulted in a marked increase in the amount of this protein in carboxysomes at the expense of M35, with a concomitant increase in the observed CcaA content of carboxysomes. Conversely, M35 over-expression diminished M58 content of carboxysomes and led to a decrease in CcaA content. Carboxysomes of air-grown wild-type cells contained slightly elevated CcaA and M58 content and slightly lower M35 content compared to their 2% CO2-grown counterparts. Over a range of CcmM expression levels, there was a strong correlation between M58 and CcaA content, indicating a constant carboxysomal M58:CcaA stoichiometry. These results also confirm a role for M58 in the recruitment of CcaA into the carboxysome and suggest a tight regulation of M35 and M58 translation is required to produce carboxysomes with an appropriate CA content. Analysis of carboxysomal protein ratios, resulting from the afore-mentioned over-expression studies, revealed that β-carboxysomal protein stoichiometries are relatively flexible. Determination of absolute protein quantities supports the hypothesis that M35 is distributed throughout the β-carboxysome. A modified β-carboxysome packing model is presented. Springer Science+Business Media B.V., 2011 Carboxysomes nationallicence RuBisCO nationallicence CCM nationallicence Carbonic anhydrase nationallicence Long Benedict Molecular Plant Physiology, Plant Science Division, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut Rae Benjamin Molecular Plant Physiology, Plant Science Division, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut Badger Murray Molecular Plant Physiology, Plant Science Division, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut Dean Price G. Molecular Plant Physiology, Plant Science Division, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut Photosynthesis Research Springer Netherlands 109/1-3(2011-09-01), 33-45 0166-8595 109:1-3<33 2011 109 11120 https://doi.org/10.1007/s11120-011-9659-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11120-011-9659-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Long Benedict Molecular Plant Physiology, Plant Science Division, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut NATIONALLICENCE 700 1- Rae Benjamin Molecular Plant Physiology, Plant Science Division, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut NATIONALLICENCE 700 1- Badger Murray Molecular Plant Physiology, Plant Science Division, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut NATIONALLICENCE 700 1- Dean Price G. Molecular Plant Physiology, Plant Science Division, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut NATIONALLICENCE 773 0- Photosynthesis Research Springer Netherlands 109/1-3(2011-09-01), 33-45 0166-8595 109:1-3<33 2011 109 11120 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer