Directed mutagenesis as a probe of photosystem II function

Conference · Tue May 01 04:00:00 EDT 1990 · Plant Physiology, Supplement; (USA)

OSTI ID:5629081

Bowlby, N; Sithole, I; McIntosh, L ^[1]; James, J; Babcock, G ^[2]

---

1. MSU-DOE Plant Research Laboratory, East Lansing, MI (USA)
2. 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--
• Conference Information: Journal Name: Plant Physiology, Supplement; (USA) Journal Volume: 93:1
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH METALS
AMINO ACIDS
BIOCHEMICAL REACTION KINETICS
CALCIUM
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CYANOBACTERIA
ELEMENTS
HYDROXY ACIDS
KINETICS
LIGANDS
MANGANESE
METALS
MICROORGANISMS
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDATION
PEPTIDES
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
POLYPEPTIDES
PROTEINS
REACTION KINETICS
SPECTROSCOPY
SYNTHESIS
TRANSITION ELEMENTS
TYROSINE