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A mutant deficient in the plastid lipid DGD is defective in protein import into chloroplasts
Author(s) -
Chen LihJen,
Li Hsoumin
Publication year - 1998
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1998.00270.x
Subject(s) - chloroplast , plastid , transit peptide , mutant , cytosol , thylakoid , biology , microbiology and biotechnology , biochemistry , protein targeting , arabidopsis , transport protein , membrane protein , gene , membrane , enzyme
Summary Most proteins in chloroplasts are encoded by the nuclear genome and synthesized in the cytosol with N‐terminal extensions called transit peptides. Transit peptides function as the import signal to chloroplasts. The import process requires several protein components in the envelope and stroma and also requires the hydrolysis of ATP. Lipids have been implicated in the import process based on theories or experiments within vitromodel systems. We show here that chloroplasts isolated from anArabidopsismutant deficient in the plastid lipid digalactosyl diacylglycerol (DGD) were normal in importing a chloroplast outer membrane protein, but were defective in importing precursor proteins targeted to the interior of chloroplasts. The impairment includes the binding, or docking, step of the import process that is supported by 100 μM ATP.