2HUG

3D Solution Structure of the Chromo-2 Domain of cpSRP43 complexed with cpSRP54 peptide


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 20 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Assembly of chloroplast signal recognition particle involves structural rearrangement in cpSRP43.

Kathir, K.M.Rajalingam, D.Sivaraja, V.Kight, A.Goforth, R.L.Yu, C.Henry, R.Kumar, T.K.

(2008) J Mol Biol 381: 49-60

  • DOI: 10.1016/j.jmb.2008.05.065
  • Primary Citation of Related Structures:  
    2HUG

  • PubMed Abstract: 
  • Signal recognition particle in chloroplasts (cpSRP) exhibits the unusual ability to bind and target full-length proteins to the thylakoid membrane. Unlike cytosolic SRPs in prokaryotes and eukaryotes, cpSRP lacks an RNA moiety and functions as a heterodimer composed of a conserved 54-kDa guanosine triphosphatase (cpSRP54) and a unique 43-kDa subunit (cpSRP43) ...

    Signal recognition particle in chloroplasts (cpSRP) exhibits the unusual ability to bind and target full-length proteins to the thylakoid membrane. Unlike cytosolic SRPs in prokaryotes and eukaryotes, cpSRP lacks an RNA moiety and functions as a heterodimer composed of a conserved 54-kDa guanosine triphosphatase (cpSRP54) and a unique 43-kDa subunit (cpSRP43). Assembly of the cpSRP heterodimer is a prerequisite for post-translational targeting activities and takes place through interactions between chromatin modifier domain 2 (CD2) of cpSRP43 and a unique 10-amino-acid region in cpSRP54 (cpSRP54(pep)). We have used multidimensional NMR spectroscopy and other biophysical methods to examine the assembly and structure of the cpSRP43-cpSRP54 interface. Our data show that CD2 of cpSRP43 binds to cpSRP54(pep) in a 1:1 stoichiometry with an apparent K(d) of approximately 1.06 muM. Steady-state fluorescence and far-UV circular dichroism data suggest that the CD2-cpSRP54(pep) interaction causes significant conformational changes in both CD2 and the peptide. Comparison of the three-dimensional solution structures of CD2 alone and in complex with cpSRP54(pep) shows that significant structural changes are induced in CD2 in order to establish a binding interface contributed mostly by residues in the N-terminal segment of CD2 (Phe5-Val10) and an arginine doublet (Arg536 and Arg537) in the cpSRP54 peptide. Taken together, our results provide new insights into the mechanism of cpSRP assembly and the structural forces that stabilize the functionally critical cpSRP43-cpSRP54 interaction.


    Organizational Affiliation

    Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Signal recognition particle 43 kDa protein, chloroplastA57Arabidopsis thalianaMutation(s): 0 
Gene Names: CAOCPSRP43At2g47450T30B22.25
UniProt
Find proteins for O22265 (Arabidopsis thaliana)
Explore O22265 
Go to UniProtKB:  O22265
Protein Feature View
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  • Reference Sequence
  • Find similar proteins by:  Sequence   |   Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Signal recognition particle 54 kDa protein, chloroplastB14Arabidopsis thalianaMutation(s): 0 
Gene Names: FFCCPSRP54At5g03940F8F6_150
UniProt
Find proteins for P37107 (Arabidopsis thaliana)
Explore P37107 
Go to UniProtKB:  P37107
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 20 
  • OLDERADO: 2HUG Olderado

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-09-18
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2020-02-19
    Changes: Data collection, Database references, Derived calculations, Other