Two distinct translocation intermediates can be distinguished during protein transport by the TAT (Δph) pathway across the thylakoid membrane
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چکیده
منابع مشابه
Energetics of Protein Transport across Biological Membranes A Study of the Thylakoid ΔpH-Dependent/cpTat Pathway
Among the pathways for protein translocation across biological membranes, the DeltapH-dependent/Tat system is unusual in its sole reliance upon the transmembrane pH gradient to drive protein transport. The free energy cost of protein translocation via the chloro-plast DeltapH-dependent/Tat pathway was measured by conducting in vitro transport assays with isolated thylakoids while concurrently m...
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In chloroplasts and bacteria, the Tat (twin-arginine translocation) system is engaged in transporting folded passenger proteins across the thylakoid and cytoplasmic membranes, respectively. To date, three membrane proteins (TatA, TatB, and TatC) have been identified to be essential for Tat-dependent protein translocation in the plant system, whereas soluble factors seem not to be required. In c...
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The thylakoid transmembrane DeltapH is the sole energy source driving translocation of precursor proteins by the DeltapH/Tat machinery. Consequently, proton translocation must be coupled to precursor translocation. For the precursor of the 17 kDa protein of the oxygen-evolving complex (pOE17), the protein translocation process is characterized by a steep drop in efficiency at an external pH bel...
متن کاملTwo distinct mechanisms for the translocation of proteins across the thylakoid membrane, one requiring the presence of a stromal protein factor and nucleotide triphosphates.
Cytosolically synthesized thylakoid lumen proteins are normally transported across the thylakoid membrane of chloroplasts as intermediate forms following cleavage of the full precursor polypeptides by a stromal peptidase. We have examined the mechanisms by which two lumenal proteins, the 33- and 23-kDa components of the oxygen-evolving complex, are translocated across the thylakoid membrane usi...
متن کاملGenetic analysis of pathway specificity during posttranslational protein translocation across the Escherichia coli plasma membrane.
In Escherichia coli, the SecB/SecA branch of the Sec pathway and the twin-arginine translocation (Tat) pathway represent two alternative possibilities for posttranslational translocation of proteins across the cytoplasmic membrane. Maintenance of pathway specificity was analyzed using a model precursor consisting of the mature part of the SecB-dependent maltose-binding protein (MalE) fused to t...
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ژورنال
عنوان ژورنال: FEBS Letters
سال: 1999
ISSN: 0014-5793
DOI: 10.1016/s0014-5793(99)01365-4