RRC ID 6305
Author Tripp J, Inoue K, Keegstra K, Froehlich JE.
Title A novel serine/proline-rich domain in combination with a transmembrane domain is required for the insertion of AtTic40 into the inner envelope membrane of chloroplasts.
Journal Plant J.
Abstract AtTic40 is part of the chloroplastic protein import apparatus that is anchored in the inner envelope membrane by a single N-terminal transmembrane domain, and has a topology in which the bulk of the C-terminal domain is oriented toward the stroma. The targeting of AtTic40 to the inner envelope membrane involves two steps. Using an in vitro import assay, we showed that the sorting of AtTic40 requires a bipartite transit peptide, which was first cleaved by the stromal processing peptidase (SPP), thus generating a soluble AtTic40 stromal intermediate (iAtTic40). iAtTic40 was further processed by a second unknown peptidase, which generates its mature form (mAtTic40). Using deletion mutants, we identified a sequence motif N-terminal of the transmembrane domain that was essential for reinsertion of iAtTic40 into the inner envelope membrane. We have designated this region a serine/proline-rich (S/P-rich) domain and present a model describing its role in the targeting of AtTic40 to the inner envelope membrane.
Volume 52(5)
Pages 824-38
Published 2007-12
DOI 10.1111/j.1365-313X.2007.03279.x
PMID 17883373
MeSH Amino Acid Sequence Arabidopsis Proteins / analysis Arabidopsis Proteins / chemistry* Arabidopsis Proteins / metabolism Chloroplasts / metabolism* Green Fluorescent Proteins / analysis Intracellular Membranes / metabolism* Membrane Proteins / analysis Membrane Proteins / chemistry* Membrane Proteins / metabolism Models, Biological Molecular Chaperones / analysis Molecular Chaperones / chemistry* Molecular Chaperones / metabolism Molecular Sequence Data Protein Sorting Signals* Protein Structure, Tertiary Protein Transport Sequence Alignment
IF 5.775
Times Cited 44
Arabidopsis / Cultured plant cells, genes pda06685