Expression in Escherichia coli of the extrinsic 18-kDa protein of photosystem II of spinach.
A cDNA encoding the precursor for the 18-kDa protein of PSII of spinach was expressed in Escherichia coli. When the cell lysate was incubated at 7 degrees C, the precursor was degraded by proteases of E. coli to a polypeptide of 18 kDa (P18) that consisted of the mature protein moiety plus the last four residues of the transit peptide. P18 was able to reconstitute the water-oxidizing complex of NaCl-treated PSII membranes supplemented with the 23-kDa protein. Moreover, P18 was cleaved by the prolyl endoproteinase of spinach specifically at the Pro-12-Leu-13 bond, as was the authentic 18-kDa protein. These properties of P18 indicate that the present expression system is potentially useful for studies of the substrate specificity of the endoproteinase, as well as of the structure-function relationships of the 18-kDa protein.
Kuwabara
T
T
Institute of Biological Sciences, University of Tsukuba, Ibaraki, Japan.
Takeuchi
M
M
Honda
S
S
Nakajima
N
N
Watanabe
A
A
Kondo
N
N
D000595:Amino Acid Sequence; D004926:Escherichia coli / Q000235:genetics; D005818:Genetic Engineering; D008969:Molecular Sequence Data; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics*; D045332:Photosystem II Protein Complex; D011498:Protein Precursors / Q000235:genetics; D016415:Sequence Alignment; D018724:Spinacia oleracea / Q000235:genetics
D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D011498:Protein Precursors