title: D1' centers are less efficient than normal photosystem II centers.
abstract: One prominent difference between the photosystem II (PSII) reaction center protein D1' in Synechocystis 6803 and normal D1 is the replacement of Phe-186 in D1 with leucine in D1'. Mutants of Synechocystis 6803 producing only D1', or containing engineered D1 proteins with Phe-186 substitutions, were analyzed by 77 K fluorescence emission spectra, chlorophyll a fluorescence induction yield and decay kinetics, and flash-induced oxygen evolution. Compared to D1-containing PSII centers, D1' centers exhibited a 50% reduction in variable chlorophyll a fluorescence yield, while the flash-induced O(2) evolution pattern was unaffected. In the F186 mutants, both the P680(+)/Q(A)(-) recombination and O(2) oscillation pattern were noticeably perturbed.
authors.affiliation: Department of Biochemistry and Biophysics, The Arrhenius Laboratories, Stockholm University, Sweden. christiane@dbb.su.se
authors.forename: C
authors.initials: C
authors.lastname: Funk
authors.forename: R
authors.initials: R
authors.lastname: Wiklund
authors.forename: W P
authors.initials: WP
authors.lastname: Schröder
authors.forename: C
authors.initials: C
authors.lastname: Jansson
mesh_terms: D019943:Amino Acid Substitution; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D000458:Cyanobacteria / Q000502:physiology*; D005453:Fluorescence; D009154:Mutation; D010100:Oxygen / Q000032:analysis / Q000378:metabolism; D010649:Phenylalanine; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics* / Q000378:metabolism; D045332:Photosystem II Protein Complex
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; C422369:photosystem II, psbA subunit; D002734:Chlorophyll; D010649:Phenylalanine; D010100:Oxygen; D000077194:Chlorophyll A