Characterization of a spinach psbS cDNA encoding the 22 kDa protein of photosystem II.
An intrinsic 22 kDa polypeptide is found associated with the oxygen-evolving photosystem II (PSII) core complex in all green plants and cyanobacteria so far examined, although it does not appear to be required for oxygen evolution. Amino acid sequence information obtained from the purified 22 kDa protein was used to construct a probe that was employed to isolate a full-length cDNA clone encoding the 274-residue precursor of the 22 kDa protein. Hydropathy plot analysis predicts the existence of four membrane-spanning helices in the mature protein. The two halves of the approximately 200-residue mature protein show high sequence similarity to each other, suggesting that the psbS gene arose from an internal gene duplication. The 22 kDa protein has some sequence similarity to chlorophyll a/b-binding proteins.
Kim
S
S
Biology Department, University of Michigan, Ann Arbor 48109.
Sandusky
P
P
Bowlby
N R
NR
Aebersold
R
R
Green
B R
BR
Vlahakis
S
S
Yocum
C F
CF
Pichersky
E
E
D000595:Amino Acid Sequence; D001483:Base Sequence; D002736:Chloroplasts / Q000502:physiology; D015342:DNA Probes; D045342:Light-Harvesting Protein Complexes; D008969:Molecular Sequence Data; D005810:Multigene Family; D010788:Photosynthesis / Q000235:genetics; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics*; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D010944:Plants / Q000235:genetics*; D017433:Protein Structure, Secondary; D017386:Sequence Homology, Amino Acid
D015342:DNA Probes; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins