Subunit stoichiometry of the chloroplast photosystem I complex

Journal Article · Wed May 25 00:00:00 EDT 1988 · J. Biol. Chem.; (United States)

OSTI ID:7192004

Bruce, B D; Malkin, R

A native photosystem I (PS I) complex and a PS I core complex depleted of antenna subunits has been isolated from the uniformly /sup 14/C-labeled aquatic higher plant, Lemna. These complexes have been analyzed for their subunit stoichiometry by quantitative sodium dodecyl sulfate-polyacrylamide gel electrophoresis methods. The results for both preparations indicate that one copy of each high molecular mass subunit is present per PS I complex and that a single copy of most low molecular mass subunits is also present. These results suggest that iron-sulfur center X, an early PS I electron acceptor proposed to bind to the high molecular mass subunits, contains a single (4Fe-4S) cluster which is bound to a dimeric structure of high molecular mass subunits, each providing 2 cysteine residues to coordinate this cluster.

• Research Organization: Univ. of California, Berkeley (USA)
• OSTI ID: 7192004
• Journal Information: J. Biol. Chem.; (United States), Vol. 263:15
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
PHOTOSYNTHETIC REACTION CENTERS
MOLECULAR STRUCTURE
STOICHIOMETRY
CARBON 14 COMPOUNDS
CHLOROPHYLL
CHLOROPLASTS
COMPLEXES
ELECTROPHORESIS
MOLECULAR WEIGHT
PLANTS
TRACER TECHNIQUES
CARBOXYLIC ACIDS
CELL CONSTITUENTS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHYTOCHROMES
PIGMENTS
PORPHYRINS
PROTEINS
550201* - Biochemistry- Tracer Techniques