The thylakoid carbonic anhydrase associated with photosystem II is the component of inorganic carbon accumulating system in cells of halo- and alkaliphilic cyanobacterium Rhabdoderma lineare.
The organization of carbonic anhydrase (CA) system in halo- and alkaliphilic cyanobacterium Rhabdoderma lineare was studied by Western blot analysis and immunocytochemical electron microscopy. The presence of putative extracellular alpha-CA of 60 kDa in the glycocalyx, forming a tight sheath around the cell, and of two intracellular beta-CA is reported. We show for the first time that the beta-CA of 60 kDa is expressed constitutively and associated with polypeptides of photosystem II (beta-CA-PS II). Another soluble beta-CA of 25 kDa was induced in low-bicarbonate medium. Induction of synthesis of the latter beta-CA was accompanied by an increase in the intracellular pool of inorganic carbon, which suggests an important role of this enzyme in the functioning of a CO(2)-concentrating mechanism.
Dudoladova
Marina V
MV
Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia.
Kupriyanova
Elena V
EV
Markelova
Alexandra G
AG
Sinetova
Maria P
MP
Allakhverdiev
Suleyman I
SI
Pronina
Natalia A
NA
D000468:Alkalies / Q000378:metabolism; D002244:Carbon / Q000378:metabolism*; D002256:Carbonic Anhydrases / Q000032:analysis* / Q000145:classification / Q000378:metabolism / Q000648:ultrastructure; D000458:Cyanobacteria / Q000166:cytology* / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure; D007150:Immunohistochemistry; D045332:Photosystem II Protein Complex / Q000737:chemistry* / Q000378:metabolism; D012492:Salts / Q000378:metabolism; D020524:Thylakoids / Q000201:enzymology* / Q000648:ultrastructure
D000468:Alkalies; D045332:Photosystem II Protein Complex; D012492:Salts; D002244:Carbon; D002256:Carbonic Anhydrases