Investigating the early stages of photosystem II assembly in Synechocystis sp. PCC 6803: isolation of CP47 and CP43 complexes.

ABSTRACT: Biochemical characterization of intermediates involved in the assembly of the oxygen-evolving Photosystem II (PSII) complex is hampered by their low abundance in the membrane. Using the cyanobacterium Synechocystis sp. PCC 6803, we describe here the isolation of the CP47 and CP43 subunits, which, during biogenesis, attach to a reaction center assembly complex containing D1, D2, and cytochrome b(559), with CP47 binding first. Our experimental approach involved a combination of His tagging, the use of a D1 deletion mutant that blocks PSII assembly at an early stage, and, in the case of CP47, the additional inactivation of the FtsH2 protease involved in degrading unassembled PSII proteins. Absorption spectroscopy and pigment analyses revealed that both CP47-His and CP43-His bind chlorophyll a

SUBMITTER: Boehm M 

PROVIDER: S-EPMC3083219 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature