Summary
The genes for cytochrome b559, designated psbE and psbF, and two highly conserved open reading frames of 38 and 42 codons have been located and characterized on the chloroplast genome of Euglena gracilis. The organization of the genes is psbE — 8 by spacer —psbF — 110 by spacer — orf38 — 87 by spacer — orf42. All genes are of the same polarity. The psbE gene contains two introns of 350 and 326 bp. The psbF gene contains a single large intron of 1,042 bp. The orf38 and orf42 loci lack introns. The introns are extremely AT rich with a pronounced base composition bias of T > A > G > C in the mRNA-like strand and group II-like boundary sequences at their 3′ and 5′ ends having the consensus 5′-GTGTG .. INTRON .. TTAATTTNAT-3′. The psbE gene consists of 82 codons and encodes a polypeptide with a predicted molecular weight of 9,212. The psbF gene consists of 42 codons, which specify a polypeptide with a predicted molecular weight of 4,785. The highly conserved open reading frames of 38 and 42 codons code for polypeptides with predicted molecular weights of 4,405 and 4,426, respectively. The gene products of psbE psbF orf38 and orf42 are, respectively, 69.5%, 70% and 61.5% identical to those found in higher plants. The predicted secondary structure of the proteins from hydropathy plots is consistent with each containing a single membrane-spanning domain of at least 20 amino acids. Each of the genes is preceded by sequences which may serve as ribosome binding sites. All four genes are transcribed.
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Abbreviations
- DEP :
-
diethyl pyrocarbonate; gene names follow the convention of Hallick and Bottomley (1983)
- psaA, psaB:
-
genes for the P700 apoproteins
- psbE and psbF:
-
genes for the subunits of cytochrome b 559
- orfN:
-
open reading frame of N codons
References
Babcock GT, Widger WR, Cramer WA, Oertling WA, Metz J (1985) Biochemistry 24:3638–3645
Butler WL (1978) FEBS Lett 95:19–25
Cantrell A, Bryant DA (1987) In: Progress in Photosynthetic Research IV10:659–662
Carrillo NP, Seyer P, Tyagi A, Herrmann RG (1986) Curr Genet 10:619–624
Cushman JC, Hallick RB, Price CA (1988) Curr Genet 13:159–171
Engelman DM, Steitz TA, Goldman A (1986) Ann Rev Biophys Chem 15:321–53
Gingrich JC, Hallick RB (1985a) J Biol Chem 260:16156–16161
Gingrich JC, Hallick RB (1985b) J Biol Chem 260:16162–16168
Hallick RB, Bottomley W (1983) Plant Mol Biol Rep 1:38–43
Herrmann RG, Alt J, Schiller B, Widger WR, Cramer WA (1984) FEBS Lett 176:239–244
Hird SM, Willey DL, Dyer TA, Gray JC (1986) Mol Gen Genet 203:95–100
Karabin GD, Farley M, Hallick RB (1984) Nucleic Acids Res 12:5801–5812
Maniatis T, Fritsch EF, Sambrook J (1982) Molecular cloning: a laboratory manual. Cold Spring Harbor Laboratory, Cold Spring Harbor New York, p 545
Matsuda H, Butler WL (1983) Biochim Biophys Acta 725:320–324
Montandon PE, Stutz E (1983) Nucleic Acids Res 11:5877–5892
Montandon P-E, Vasserot A, Stutz E (1986) Curr Genet 11:35–39
Nanba O, Satoh K (1987) Proc Natl Acad Sci USA 84:109–112
Ohyama K, Fukuzawa H, Kohchi T, Shirai H, Sano T, Sano S, Umesono K, Shiki Y, Takeuchi M, Chang Z, Aota S, Inokuchi H, Ozeki H (1986) Nature 322:572–574
Passavant CW, Hallick RB (1985) Plant Mol Biol 4:347–554
Price CA, Reardon EM (1982) In: Edelman M, Hallick RB, Chua N-H (eds) Methods in chloroplast molecular biology. Elsevier-Biomedical, New York, pp 189–209
Sasaki Y, Ishiye M, Sakihama T, Kamihubo T (1983) J Biol Chem 256:2315–2320
Satoh K (1985) Photochem Photobiol 42:845–853
Shinozaki K, Ohme M, Tanaka M, Wakasugi T, Hayashida N, Matsubayashi T, Zaita N, Chunwongse J, Obokata J, Yamaguchi-Shinozaki K, Ohto C, Torazawa K, Meng BY, Sugita M, Deno H, Kamogashira T, Yamada K, Kusuda J, Takaiwa F, Kato A, Tohdoh N, Shimada H, Sugiura M (1986) EMBO J 5:2043–2049
Steege DA, Graves MC, Spermulli LL (1982) J Biol Chem 257:10430–10439
Westhoff P, Alt J, Widger WR, CramerWA, Herrmann RG (1985) Plant Mol Biol 4:103–110
Widger WR, Cramer WA, Hermodson M, Meyer D, Gullifor M (1984) J Biol Chem 259:3870–3876
Widger WR, Cramer WA, Hermodson M, Herrmann RG (1985) FEBS Lett 191:186–190
Zielinski RE, Price CA (1980) J Cell Biol 85:435–445
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Cushman, J.C., Christopher, D.A., Little, M.C. et al. Organization of the psbE, psbF, orf38, and orf42 gene loci on the Euglena gracilis chloroplast genome. Curr Genet 13, 173–180 (1988). https://doi.org/10.1007/BF00365652
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DOI: https://doi.org/10.1007/BF00365652