title: Chlorophyll b inhibits the formation of photosystem I trimer in Synechocystis sp. PCC6803.
abstract: Chlorophyllide a oxygenase (CAO) catalyzes two-step oxygenation reactions and converts chlorophyllide a to chlorophyllide b. When CAO was introduced into the Synechocystis sp. PCC6803 genome, chlorophyll b was synthesized and incorporated into P700-chlorophyll a-protein complexes. Curve analysis of photosystem I particles showed that Ca687 was decreased with a concomitant increase in Cb652 suggesting that chlorophyll b was incorporated into Ca687-binding sites. When the level of chlorophyll b was high, Ca704, which is known as red chlorophyll and photosystem I trimers were decreased. Formation of photosystem I trimers is discussed in relation to red chlorophyll and chlorophyll b accumulation.
authors.affiliation: The Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan. ssato@snowbell.lowtem.hokudai.ac.jp
authors.forename: Soichirou
authors.initials: S
authors.lastname: Satoh
authors.forename: Ayumi
authors.initials: A
authors.lastname: Tanaka
mesh_terms: D001665:Binding Sites; D002734:Chlorophyll / Q000378:metabolism*; D000077194:Chlorophyll A; D002735:Chlorophyllides / Q000378:metabolism; D000458:Cyanobacteria / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial; D009154:Mutation; D010105:Oxygenases / Q000235:genetics / Q000378:metabolism; D045322:Photosynthetic Reaction Center Complex Proteins / Q000096:biosynthesis* / Q000737:chemistry*; D020836:Protein Structure, Quaternary; D013053:Spectrophotometry
chemical_list: D002735:Chlorophyllides; D045322:Photosynthetic Reaction Center Complex Proteins; D002734:Chlorophyll; C046016:chlorophyllide b; C037184:chlorophyll b; D010105:Oxygenases; C115272:chlorophyll a oxygenase; D000077194:Chlorophyll A