Đang chuẩn bị nút TẢI XUỐNG, xin hãy chờ
Tải xuống
The N-termini of the NADPH : protochlorophyllide oxidoreductase (POR) proteins A and B from barley and POR from pea were determined by acet-ylation of the proteins and selective isolation of the N-terminal peptides for mass spectrometry de novosequence analysis. We show that the cleav-age sites between the transit peptides and the three mature POR proteins are homologous. | ễFEBS Journal Identification of the N-termini of NADPH protochlorophyllide oxidoreductase A and B from barley etioplasts Hordeum vulgare L. Matthias Ploscher1 Bernhard Granvogl1 Veronika Reisinger1 and Lutz A. Eichacker2 1 Department of Biology I Ludwig-Maximilians-University Munich Germany 2 Center for Organelle Research CORE Universitetet i Stavanger Norway Keywords etioplast N-terminus PORA protochlorophyllide oxidoreductase transit peptide Correspondence L. A. Eichacker Center for Organelle Research CORE Universitetet I Stavanger Kristine Bonnevis vei 22 N-4036 Stavanger Norway Fax 47 518 31860 Tel 47 518 31896 E-mail lutz.eichacker@uis.no Received 11 October 2008 revised 7 December 2008 accepted 10 December 2008 The N-termini of the NADPH protochlorophyllide oxidoreductase POR proteins A and B from barley and POR from pea were determined by acetylation of the proteins and selective isolation of the N-terminal peptides for mass spectrometry de novo sequence analysis. We show that the cleavage sites between the transit peptides and the three mature POR proteins are homologous. The N-terminus in PORA is V48 that in PORB is A61 and that in POR from pea is E64. For the PORB protein two additional N-termini were identified as A62 and A63 with decreased signal intensity of the corresponding N-terminal peptides. The results show that the transit peptide of PORA is considerably shorter than previously reported and predicted by ChloroP. A pentapeptide motif that has been characterized as responsible for binding of protochlorophyllide to the transit peptide of PORA Reinbothe C Pollmann S Phetsarath-Faure P Quigley F Weis-beek P Reinbothe S 2008 Plant Physiol 148 694-703 is shown here to be part of the mature PORA protein. doi 10.1111 j.1742-4658.2008.06850.x The first step of plant greening is catalysed by NADPH protochlorophyllide oxidoreductase POR which is one of the most abundant enzymes found in etioplasts. The enzyme catalyses the light-activated reduction of .
