
%0 Journal Article
%A Nicoll, Wil 
%A Eaton-Rye, Julian 
%T Deletions in the lumenal domains of the D1 protein that prevent the assembly of photosystem II in Synechocystis sp. PCC 6803
%J Science Access
%D 2001/01/01
%V 3
%N 1
%P -
%K 
%R https://doi.org/10.1071/SA0403340
%U https://www.publish.csiro.au/paper/SA0403340 
%X The photosystem II (PSII) proteins, D1 and CP47, contribute hydrophilic domains to the water-oxidizing complex (WOC). We have constructed a deletion mutant system that allows us to introduce mutations into psbA2, encoding D1. Initially we introduced short deletions of 3 to 6 amino acids that targeted alkoxo and phenoxo groups from Ser and Tyr residues creating the strains: D1:?(Y73-S79); D1:?(V82-S86); D1:?(Y107-G109); D1:?(L174-S177) and D1:?(F302-S305); however, PSII was not assembled in these mutants. In addition, we created the mutant D1:T292L which exhibited a phenotype similar to wild type. However, removal of PSII-V (or cytochrome c-550) abolished photoautotrophic growth in the D1:T292L:?PSII-V strain in a pH dependent fashion: no growth was observed at pH 8.0 but it was restored at pH 10. The Arg-384 to Val-392 region of CP47 has been shown to influence the tight binding of PSII-O (or the manganese-stabilizing protein) to the WOC. Mutations were introduced that created the strains: CP47:E387R; CP47:S388A; CP47:K389E; CP47:K389Q and CP47:S391R. Each of these mutants were characterized in the presence or absence of PSII-O, PSII-U and PSII-V; and, mutations at Ser-388, Lys-389 and Ser-391 resulted in a phenotype similar to wild type or a control strain lacking the corresponding extrinsic protein. However, deletion of PSII-V from CP47:E387R resulted in an obligate photohetrotrophic strain that did not assemble PSII when grown at pH 8.0. However, growth of CP47:E387R:?PSII-V cells at pH 10 restored PSII assembly and photoautotrophic growth. We are testing if mutations at D1:Thr-292 and CP47:Glu-387 are additive when introduced in the same strain. 
