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Determinants for cleavage of the chlorophyll a/b binding protein precursor: a requirement for a basic residue that is not universal for chloroplast imported proteins
We demonstrate that the precursor of the major light-harvesting chlorophyll a/b binding protein (LHCP of Photosystem II), encoded by a Type I gene, contains distinct determinants for processing at two sites during in vitro import into the chloroplast. Using precursors from both pea and wheat, it is...
Formato: | Texto |
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Lenguaje: | English |
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The Rockefeller University Press
1991
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2289902/ https://www.ncbi.nlm.nih.gov/pubmed/1869585 |
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collection | PubMed |
description | We demonstrate that the precursor of the major light-harvesting chlorophyll a/b binding protein (LHCP of Photosystem II), encoded by a Type I gene, contains distinct determinants for processing at two sites during in vitro import into the chloroplast. Using precursors from both pea and wheat, it is shown that primary site processing, and release of a approximately 26-kD peptide, depends on an amino-proximal basic residue. Substitution of an arginine at position -4 resulted in an 80% reduction in processing, with the concomitant accumulation of a high molecular weight intermediate. Cleavage occurred normally when arginine was changed to lysine. The hypothesis that a basic residue is a general requirement for transit peptide removal was tested. We find that the precursors for the small subunit of Rubisco and Rubisco activase do not require a basic residue within seven amino acids of the cleavage site for maturation. In the wheat LHCP precursor, determinants for efficient cleavage at a secondary site were identified carboxy to the primary site, beyond what is traditionally called the transit peptide, within the sequence ala-lys-ala-lys (residues 38-41). Introduction of this sequence into the pea precursor, which has the residues thr-thr-lys-lys in the corresponding position, converted it to a substrate with an efficiently recognized secondary site. Our results indicate that two different forms of LHCP can be produced with distinct NH2-termini by selective cleavage of a single precursor polypeptide. |
format | Text |
id | pubmed-2289902 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1991 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-22899022008-05-01 Determinants for cleavage of the chlorophyll a/b binding protein precursor: a requirement for a basic residue that is not universal for chloroplast imported proteins J Cell Biol Articles We demonstrate that the precursor of the major light-harvesting chlorophyll a/b binding protein (LHCP of Photosystem II), encoded by a Type I gene, contains distinct determinants for processing at two sites during in vitro import into the chloroplast. Using precursors from both pea and wheat, it is shown that primary site processing, and release of a approximately 26-kD peptide, depends on an amino-proximal basic residue. Substitution of an arginine at position -4 resulted in an 80% reduction in processing, with the concomitant accumulation of a high molecular weight intermediate. Cleavage occurred normally when arginine was changed to lysine. The hypothesis that a basic residue is a general requirement for transit peptide removal was tested. We find that the precursors for the small subunit of Rubisco and Rubisco activase do not require a basic residue within seven amino acids of the cleavage site for maturation. In the wheat LHCP precursor, determinants for efficient cleavage at a secondary site were identified carboxy to the primary site, beyond what is traditionally called the transit peptide, within the sequence ala-lys-ala-lys (residues 38-41). Introduction of this sequence into the pea precursor, which has the residues thr-thr-lys-lys in the corresponding position, converted it to a substrate with an efficiently recognized secondary site. Our results indicate that two different forms of LHCP can be produced with distinct NH2-termini by selective cleavage of a single precursor polypeptide. The Rockefeller University Press 1991-08-02 /pmc/articles/PMC2289902/ /pubmed/1869585 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Articles Determinants for cleavage of the chlorophyll a/b binding protein precursor: a requirement for a basic residue that is not universal for chloroplast imported proteins |
title | Determinants for cleavage of the chlorophyll a/b binding protein precursor: a requirement for a basic residue that is not universal for chloroplast imported proteins |
title_full | Determinants for cleavage of the chlorophyll a/b binding protein precursor: a requirement for a basic residue that is not universal for chloroplast imported proteins |
title_fullStr | Determinants for cleavage of the chlorophyll a/b binding protein precursor: a requirement for a basic residue that is not universal for chloroplast imported proteins |
title_full_unstemmed | Determinants for cleavage of the chlorophyll a/b binding protein precursor: a requirement for a basic residue that is not universal for chloroplast imported proteins |
title_short | Determinants for cleavage of the chlorophyll a/b binding protein precursor: a requirement for a basic residue that is not universal for chloroplast imported proteins |
title_sort | determinants for cleavage of the chlorophyll a/b binding protein precursor: a requirement for a basic residue that is not universal for chloroplast imported proteins |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2289902/ https://www.ncbi.nlm.nih.gov/pubmed/1869585 |