Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 26.25 kDa 
• Atom Count: 1613 
• Modelled Residue Count: 200 
• Deposited Residue Count: 238 
• Unique protein chains: 1

4YE0

Stress-induced protein 1 truncation mutant (43 - 140) from Caenorhabditis elegans

• PDB DOI: 10.2210/pdb4YE0/pdb

• Classification: CHAPERONE
• Organism(s): Caenorhabditis elegans
• Expression System: Escherichia coli BL21
• Mutation(s): No 


• Deposited: 2015-02-23 Released: 2015-06-10 
• Deposition Author(s): Fleckenstein, T., Kastenmueller, A., Stein, M.L., Peters, C., Daake, M., Krause, M., Weinfurtner, D., Haslbeck, M., Weinkauf, S., Groll, M., Buchner, J.
• Funding Organization(s): DFG

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.10 Å
• R-Value Free: 0.259 
• R-Value Work: 0.230 
• R-Value Observed: 0.232 

Literature

The Chaperone Activity of the Developmental Small Heat Shock Protein Sip1 Is Regulated by pH-Dependent Conformational Changes.

Fleckenstein, T., Kastenmuller, A., Stein, M.L., Peters, C., Daake, M., Krause, M., Weinfurtner, D., Haslbeck, M., Weinkauf, S., Groll, M., Buchner, J.

(2015) Mol Cell 58: 1067-1078

• PubMed: 26009280 
• DOI: 10.1016/j.molcel.2015.04.019
• Primary Citation of Related Structures:  
  4YDZ, 4YE0


• PubMed Abstract: 
  

Small heat shock proteins (sHsps) are ubiquitous molecular chaperones that prevent the aggregation of unfolding proteins during proteotoxic stress. In Caenorhabditis elegans, Sip1 is the only sHsp exclusively expressed in oocytes and embryos. Here, we demonstrate that Sip1 is essential for heat shock survival of reproducing adults and embryos. X-ray crystallography and electron microscopy revealed that Sip1 exists in a range of well-defined globular assemblies consisting of two half-spheres, each made of dimeric "spokes." Strikingly, the oligomeric distribution of Sip1 as well as its chaperone activity depend on pH, with a trend toward smaller species and higher activity at acidic conditions such as present in nematode eggs. The analysis of the interactome shows that Sip1 has a specific substrate spectrum including proteins that are essential for embryo development.

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Organizational Affiliation: 

Center for Integrated Protein Science, Fakultät für Chemie, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany. Electronic address: [e-mail].

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Stress-induced protein 1	A, B	119	Caenorhabditis elegans	Mutation(s): 0  Gene Names: sip-1, F43D9.4
UniProt
Find proteins for Q20363 (Caenorhabditis elegans) Explore Q20363  Go to UniProtKB:  Q20363

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
SO4	C [auth A], D [auth B]	SULFATE ION O4 S QAOWNCQODCNURD-UHFFFAOYSA-L

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.10 Å
• R-Value Free: 0.259 
• R-Value Work: 0.230 
• R-Value Observed: 0.232 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 36.39	α = 90
b = 50.82	β = 90
c = 130.17	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
XDS	data reduction
PHASER	phasing

Structure Validation

Entry History & Funding Information

Deposition Data

• Deposited Date: 2015-02-23 
• Released Date: 2015-06-10 
Deposition Author(s): Fleckenstein, T., Kastenmueller, A., Stein, M.L., Peters, C., Daake, M., Krause, M., Weinfurtner, D., Haslbeck, M., Weinkauf, S., Groll, M., Buchner, J.

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Funding Organization	Location	Grant Number
DFG	Germany	SFB1035

Revision History  

• Version 1.0: 2015-06-10
  Type: Initial release
  
• Version 1.1: 2015-07-01
  Changes: Database references