PRIMARY STRUCTURE AND POSTTRANSLATIONAL MODIFICATION OF FERREDOXIN-NADP REDUCTASE FROM CHLAMYDOMONAS-REINHARDTII

The flavoprotein ferredoxin-NADP reductase (FNR) was isolated from the unicellular green alga, Chlamydomonas reinhardtii, FNR is a monomeric protein containing one FAD and exhibiting ferredoxin-dependent cytoch rome c reduction activity, Its complete primary structure was investig ated by sequencing overlapping peptides generated by cleavage with try psin and SV8 protease and confirmed by partial (80%) nucleotidic seque nce, C. reinhardtii FNR contains 320 residues, coresponding to a calcu lated mass of 35,685 and 36,470 including FAD, in agreement with the v alues measured by laser desorption mass spectrometry, The combination of both amino acid and nucleotidic sequencing, in association with mas s spectrometry of peptides, allowed the identification of two N epsilo n-trimethyllysines at positions 83 and 89 and one N epsilon-dimethylly sine at position 135, Comparison of the primary structure of C, reinha rdtii FNR with the known sequences shows 41-46% identity. (C) 1995 Aca demic Press, Inc.