| Structural highlights
Function
[SR43C_ARATH] Component of the chloroplast signal recognition particle pathway. Required for post-translational targeting of proteins into the tylakoid membrane but seems to be dispensable for co-translational targeting with a translating ribosome present. May be able to function independently of cpFTSY and FFC/cpSRP54 in targeting LHCPs to the thylakoids. Acts as a highly specific chaperone for LHCPs, preventing aggregation and being able to dissolve aggregates.[1] [2] [3] [4] [5]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Secretory and membrane proteins carry amino-terminal signal sequences that, in cotranslational targeting, are recognized by the signal recognition particle protein SRP54 without sequence specificity. The most abundant membrane proteins on Earth are the light-harvesting chlorophyll a/b binding proteins (LHCPs). They are synthesized in the cytoplasm, imported into the chloroplast, and posttranslationally targeted to the thylakoid membrane by cpSRP, a heterodimer formed by cpSRP54 and cpSRP43. We present the 1.5 angstrom crystal structure of cpSRP43 characterized by a unique arrangement of chromodomains and ankyrin repeats. The overall shape and charge distribution of cpSRP43 resembles the SRP RNA, which is absent in chloroplasts. The complex with the internal signal sequence of LHCPs reveals that cpSRP43 specifically recognizes a DPLG peptide motif. We describe how cpSPR43 adapts the universally conserved SRP system to posttranslational targeting and insertion of the LHCP family of membrane proteins.
Structural basis for specific substrate recognition by the chloroplast signal recognition particle protein cpSRP43.,Stengel KF, Holdermann I, Cain P, Robinson C, Wild K, Sinning I Science. 2008 Jul 11;321(5886):253-6. PMID:18621669[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Klimyuk VI, Persello-Cartieaux F, Havaux M, Contard-David P, Schuenemann D, Meiherhoff K, Gouet P, Jones JD, Hoffman NE, Nussaume L. A chromodomain protein encoded by the arabidopsis CAO gene is a plant-specific component of the chloroplast signal recognition particle pathway that is involved in LHCP targeting. Plant Cell. 1999 Jan;11(1):87-99. PMID:9878634
- ↑ Tu CJ, Schuenemann D, Hoffman NE. Chloroplast FtsY, chloroplast signal recognition particle, and GTP are required to reconstitute the soluble phase of light-harvesting chlorophyll protein transport into thylakoid membranes. J Biol Chem. 1999 Sep 17;274(38):27219-24. PMID:10480939
- ↑ Goforth RL, Peterson EC, Yuan J, Moore MJ, Kight AD, Lohse MB, Sakon J, Henry RL. Regulation of the GTPase cycle in post-translational signal recognition particle-based protein targeting involves cpSRP43. J Biol Chem. 2004 Oct 8;279(41):43077-84. Epub 2004 Aug 2. PMID:15292240 doi:http://dx.doi.org/10.1074/jbc.M401600200
- ↑ Tzvetkova-Chevolleau T, Hutin C, Noel LD, Goforth R, Carde JP, Caffarri S, Sinning I, Groves M, Teulon JM, Hoffman NE, Henry R, Havaux M, Nussaume L. Canonical signal recognition particle components can be bypassed for posttranslational protein targeting in chloroplasts. Plant Cell. 2007 May;19(5):1635-48. Epub 2007 May 18. PMID:17513500 doi:http://dx.doi.org/10.1105/tpc.106.048959
- ↑ Falk S, Sinning I. cpSRP43 is a novel chaperone specific for light-harvesting chlorophyll a,b-binding proteins. J Biol Chem. 2010 Jul 9;285(28):21655-61. doi: 10.1074/jbc.C110.132746. Epub 2010, May 24. PMID:20498370 doi:http://dx.doi.org/10.1074/jbc.C110.132746
- ↑ Stengel KF, Holdermann I, Cain P, Robinson C, Wild K, Sinning I. Structural basis for specific substrate recognition by the chloroplast signal recognition particle protein cpSRP43. Science. 2008 Jul 11;321(5886):253-6. PMID:18621669 doi:321/5886/253
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