Abstract
Using λgt11 expression cloning and immunoscreening, cDNA-containing recombinant phages for subunits IV and V of the photosystem I reaction center were isolated, sequenced and used to probe Northern blots of polyadenylated RNA prepared from spinach seedlings. The mRNA sizes for both components are ∼ 1000 and 850 nucleotides, respectively. The 968 nucleotide cDNA sequence and derived amino acid sequence for subunit IV predict a single open reading frame of 231 amino acid residues (25.4 kDa). Comparison with a 13-residue N-terminal amino acid sequence determined for subunit IV suggests a mature protein of 17.3 kDa (154 residues) and a transit sequence of 77 amino acids (8.1 kDa). The corresponding data for subunit V are 677 bp (cDNA), 167 residues for the precursor protein (18.2 kDa), 98 residues for the mature polypeptide (10.8 kDa) and 69 residues for the transit peptide (7.4 kDa). Secondary structure predictions indicate that both proteins possess greatly different transit sequences and that none is membrane-spanning.
Original language | English |
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Pages (from-to) | 218-224 |
Number of pages | 7 |
Journal | FEBS Letters |
Volume | 237 |
Issue number | 1-2 |
DOIs | |
State | Published - 12 Sep 1988 |
Bibliographical note
Funding Information:AcknowledgementTsh: e technical assistance of MS Christa Jansen is gratefully acknowledged. The work was supported by the German Research Foundation (grant He623/12-2; SFB 184) and the Fonds der Chemischen Industrie.
Keywords
- (Spinach)
- Nucleotide sequence
- Photosynthesis
- Photosystem I
- Subunit
- cDNA