Directed mutagenesis as a probe of photosystem II function
- MSU-DOE Plant Research Laboratory, East Lansing, MI (USA)
- Michigan State Univ., East Lansing (USA)
Several mutants of Synechocystis 6803 have been generated by site-directed mutagenesis of psbA and psbD in order to study the roles of the D1 and D2 proteins during H{sub 2}O oxidation. Of key importance to these studies is the analysis of PSII electron transfer components such as Y{sub Z}{sup +} and Y{sub D}{sup +}, and the identification of possible ligands to Mn and Ca. Detailed information can be gained through EPR spectroscopy, however, sensitivity is limited by the PSII concentration of the sample. A simple procedure for the purification of PSII from this cyanobacterium, in sufficient amounts for EPR studies, will be presented. Preliminary results from mutant analysis extend the characterization of the two tyrosine radicals and suggest an important structural role for Pro{sup 162} of D1 and Pro{sup 161} of D2 in the ability of the photosystem to form the radical species on the adjacent tyrosine residues Tyr{sup 161} and Tyr{sup 160} on D1 and D2 respectively.
- OSTI ID:
- 5629081
- Report Number(s):
- CONF-9007196-; CODEN: PPYSA
- Journal Information:
- Plant Physiology, Supplement; (USA), Vol. 93:1; Conference: Annual meeting of the American Society of Plant Physiologists, Indianapolis, IN (USA), 29 Jul - 2 Aug 1990; ISSN 0079-2241
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CYANOBACTERIA
BIOCHEMICAL REACTION KINETICS
CALCIUM
LIGANDS
MANGANESE
OXIDATION
PHOTOSYNTHESIS
POLYPEPTIDES
SPECTROSCOPY
TYROSINE
ALKALINE EARTH METALS
AMINO ACIDS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
ELEMENTS
HYDROXY ACIDS
KINETICS
METALS
MICROORGANISMS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PEPTIDES
PHOTOCHEMICAL REACTIONS
PROTEINS
REACTION KINETICS
SYNTHESIS
TRANSITION ELEMENTS
550200* - Biochemistry