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. 1993 Aug;102(4):1259–1267. doi: 10.1104/pp.102.4.1259

Molecular heterogeneity of photosystem I. psaD, psaE, psaF, psaH, and psaL are all present in isoforms in Nicotiana spp.

J Obokata 1, K Mikami 1, N Hayashida 1, M Nakamura 1, M Sugiura 1
PMCID: PMC158913  PMID: 8278548

Abstract

The protein composition of photosystem I (PSI) was examined in Nicotiana spp. by high-resolution polyacrylamide gel electrophoresis, N-terminal amino acid sequencing, and immunoblot analysis. Five PSI proteins show polymorphism in an amphidiploid species, Nicotiana tabacum, but not in its ancestral diploid species, Nicotiana sylvestris and Nicotiana tomentosiformis. These Nicotiana spp. appear to have at least 18 PSI proteins per genome that range in molecular mass from 3 to 20 kD. They include the products of nuclear genes psaD, psaE, psaF, psaG, psaH, psaK, and psaL, the product of chloroplast gene psaC, N-terminally blocked proteins of 4.5 and 3.0 kD, and an unidentified protein of 12.5 kD. The psaD, psaF, psaH, and psaL products have two isoforms each that are distinguished by different mobilities in polyacrylamide gel electrophoresis, and the psaE product has four isoforms. The two isoforms of the psaD product have distinct amino acid sequences, indicating that they are encoded by different genes within the genome. Four isoforms of the psaE products can be classified into two groups by N-terminal amino acid sequence, indicating that at least two psaE genes are present in the genome. To examine whether the polymorphic nature of PSI is peculiar to Nicotiana spp., we carried out immunoblot analysis of the psaD and psaE products in isogenic lines of tomato (Lycopersicon esculentum), Arabidopsis thaliana, red bean (Vigna angularis), and corn (Zea mays). Two electrophoretically distinct isoforms were found for the psaD products of tomato, A. thaliana, and corn, and two isoforms of psaE products were detected in tomato, A. thaliana, and red bean. These results suggest that the nuclear-encoded subunits of PSI, except for the psaG and psaK products, generally have two isoforms.

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Selected References

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  1. Chitnis P. R., Purvis D., Nelson N. Molecular cloning and targeted mutagenesis of the gene psaF encoding subunit III of photosystem I from the cyanobacterium Synechocystis sp. PCC 6803. J Biol Chem. 1991 Oct 25;266(30):20146–20151. [PubMed] [Google Scholar]
  2. Chitnis P. R., Reilly P. A., Miedel M. C., Nelson N. Structure and targeted mutagenesis of the gene encoding 8-kDa subunit of photosystem I from the cyanobacterium Synechocystis sp. PCC 6803. J Biol Chem. 1989 Nov 5;264(31):18374–18380. [PubMed] [Google Scholar]
  3. Fling S. P., Gregerson D. S. Peptide and protein molecular weight determination by electrophoresis using a high-molarity tris buffer system without urea. Anal Biochem. 1986 May 15;155(1):83–88. doi: 10.1016/0003-2697(86)90228-9. [DOI] [PubMed] [Google Scholar]
  4. Gray J. C., Kung S. D., Wildman S. G. Origin of Nicotiana tabacum L. detected by polypeptide composition of Fraction I protein. Nature. 1974 Nov 15;252(5480):226–227. doi: 10.1038/252226a0. [DOI] [PubMed] [Google Scholar]
  5. Hase T., Mizutani S., Mukohata Y. Expression of Maize Ferredoxin cDNA in Escherichia coli: Comparison of Photosynthetic and Nonphotosynthetic Ferredoxin Isoproteins and their Chimeric Molecule. Plant Physiol. 1991 Dec;97(4):1395–1401. doi: 10.1104/pp.97.4.1395. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Ikeuchi M., Inoue Y. Two new components of 9 and 14 kDa from spinach photosystem I complex. FEBS Lett. 1991 Mar 25;280(2):332–334. doi: 10.1016/0014-5793(91)80324-v. [DOI] [PubMed] [Google Scholar]
  7. Iwasaki Y., Ishikawa H., Hibino T., Takabe T. Characterization of genes that encode subunits of cucumber PS I complex by N-terminal sequencing. Biochim Biophys Acta. 1991 Aug 23;1059(2):141–148. doi: 10.1016/s0005-2728(05)80198-7. [DOI] [PubMed] [Google Scholar]
  8. Kelly J. L., Greenleaf A. L., Lehman I. R. Isolation of the nuclear gene encoding a subunit of the yeast mitochondrial RNA polymerase. J Biol Chem. 1986 Aug 5;261(22):10348–10351. [PubMed] [Google Scholar]
  9. Obokata J., Mikami K., Hayashida N., Sugiura M. Polymorphism of a photosystem I subunit caused by alloploidy in Nicotiana. Plant Physiol. 1990 Jan;92(1):273–275. doi: 10.1104/pp.92.1.273. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Obokata J. Synthesis and Assembly of the Polypeptides of Photosystem I and II in Isolated Etiochloroplasts of Wheat. Plant Physiol. 1987 Jun;84(2):535–540. doi: 10.1104/pp.84.2.535. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Okkels J. S., Scheller H. V., Svendsen I., Møller B. L. Isolation and characterization of a cDNA clone encoding an 18-kDa hydrophobic photosystem I subunit (PSI-L) from barley (Hordeum vulgare L.). J Biol Chem. 1991 Apr 15;266(11):6767–6773. [PubMed] [Google Scholar]
  12. Reilly P., Hulmes J. D., Pan Y. C., Nelson N. Molecular cloning and sequencing of the psaD gene encoding subunit II of photosystem I from the cyanobacterium, Synechocystis sp. PCC 6803. J Biol Chem. 1988 Nov 25;263(33):17658–17662. [PubMed] [Google Scholar]
  13. Shimada H., Sugiura M. Fine structural features of the chloroplast genome: comparison of the sequenced chloroplast genomes. Nucleic Acids Res. 1991 Mar 11;19(5):983–995. doi: 10.1093/nar/19.5.983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Wynn R. M., Malkin R. Interaction of plastocyanin with photosystem I: a chemical cross-linking study of the polypeptide that binds plastocyanin. Biochemistry. 1988 Aug 9;27(16):5863–5869. doi: 10.1021/bi00416a007. [DOI] [PubMed] [Google Scholar]
  15. Yamamoto Y., Tsuji H., Hayashida N., Inoue K., Obokata J. Nucleotide sequence of cDNA clones encoding PSI-D2 protein of photosystem I in Nicotiana sylvestris. Plant Mol Biol. 1991 Dec;17(6):1251–1254. doi: 10.1007/BF00028741. [DOI] [PubMed] [Google Scholar]
  16. Zanetti G., Merati G. Interaction between photosystem I and ferredoxin. Identification by chemical cross-linking of the polypeptide which binds ferredoxin. Eur J Biochem. 1987 Nov 16;169(1):143–146. doi: 10.1111/j.1432-1033.1987.tb13591.x. [DOI] [PubMed] [Google Scholar]
  17. Zilber A. L., Malkin R. Ferredoxin Cross-Links to a 22 kD Subunit of Photosystem I. Plant Physiol. 1988 Nov;88(3):810–814. doi: 10.1104/pp.88.3.810. [DOI] [PMC free article] [PubMed] [Google Scholar]

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