title: The effect of amino acid-modifying reagents on chloroplast protein import and the formation of early import intermediates.
abstract: In order to identify functionally important amino acid residues in the chloroplast protein import machinery, chloroplasts were preincubated with amino-acid-modifying reagents and then allowed to import or form early import intermediates with precursor proteins. Incubation of chloroplasts with N-ethyl maleimide, diethyl pyrocarbonate, phenylglyoxal, 4,4'-di-isothiocyanatostilbene 2,2'-disulphonic acid (DIDS), dicyclohexylcarbodiimide (DCCD), and 1-ethyl- 3-dimethylaminopropylcarbodiimide (EDC) inhibited both import and formation of early import intermediates with precursor proteins by chloroplasts. This suggests that one or more of the binding components of the chloroplast protein import machinery contains functionally important solvent-exposed cysteine, histidine, arginine, and aspartate/glutamate residues, as well as functionally important lysine and aspartate/ glutamate residues in a hydrophobic environment.
authors.affiliation: Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.
authors.forename: P E
authors.initials: PE
authors.lastname: Row
authors.forename: J C
authors.initials: JC
authors.lastname: Gray
mesh_terms: D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000494:pharmacology; D000596:Amino Acids; D060365:Chloroplast Proteins; D002736:Chloroplasts / Q000187:drug effects / Q000378:metabolism*; D003432:Cross-Linking Reagents; D004024:Dicyclohexylcarbodiimide / Q000037:antagonists & inhibitors / Q000493:pharmacokinetics; D004047:Diethyl Pyrocarbonate / Q000494:pharmacology; D004586:Electrophoresis; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005022:Ethyldimethylaminopropyl Carbodiimide / Q000031:analogs & derivatives / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D005287:Ferredoxin-NADP Reductase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D026901:Membrane Transport Proteins; D018532:Pisum sativum / Q000378:metabolism; D010658:Phenylglyoxal / Q000494:pharmacology; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D010957:Plasmids; D011498:Protein Precursors / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012273:Ribulose-Bisphosphate Carboxylase / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000596:Amino Acids; D060365:Chloroplast Proteins; D003432:Cross-Linking Reagents; D004791:Enzyme Inhibitors; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D010940:Plant Proteins; D011498:Protein Precursors; C101484:import intermediate associated protein 100; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D004024:Dicyclohexylcarbodiimide; C041829:1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide methiodide; D005287:Ferredoxin-NADP Reductase; D012273:Ribulose-Bisphosphate Carboxylase; D004047:Diethyl Pyrocarbonate; D010658:Phenylglyoxal; D005033:Ethylmaleimide; D005022:Ethyldimethylaminopropyl Carbodiimide