1AEI | pdb_00001aei

CRYSTAL STRUCTURE OF THE ANNEXIN XII HEXAMER

• PDB DOI: https://doi.org/10.2210/pdb1AEI/pdb

• Classification: CALCIUM/PHOSPHOLIPID-BINDING
• Organism(s): Hydra vulgaris
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 1995-09-23 Released: 1997-08-20 
• Deposition Author(s): Luecke, H., Chang, B.T., Mailliard, W.S., Schlaepfer, D.D., Haigler, H.T.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Free: 
  0.278 (Depositor) 
• R-Value Work: 
  0.236 (Depositor) 
• R-Value Observed: 
  0.236 (Depositor) 

Starting Model: experimental

Literature

Crystal structure of the annexin XII hexamer and implications for bilayer insertion.

Luecke, H., Chang, B.T., Mailliard, W.S., Schlaepfer, D.D., Haigler, H.T.

(1995) Nature 378: 512-515

• PubMed: 7477411 
• DOI: https://doi.org/10.1038/378512a0
• Primary Citation Related Structures: 
  1AEI


• PubMed Abstract: 
  

  Annexins are a family of calcium- and phospholipid-binding proteins implicated in a number of biological processes including membrane fusion and ion channel formation. The crystal structure of the annexin XII hexamer, refined at 2.8 A resolution, forms a concave disk with 3-2 symmetry, about 100 A in diameter and 70 A thick with a central hydrophilic pore. Six intermolecular Ca2+ ions are involved in hexamer formation. An additional 18 Ca2+ ions are located on the perimeter of the disk, accessible only from the side of the hexameric disk. On the basis of the hexamer structure we propose here a new mode of protein-phospholipid bilayer interaction that is distinct from the hydrophobic insertion of typical membrane proteins. This speculative model postulates the Ca(2+)-dependent insertion of the hydrophilic annexin XII hexamer into phospholipid bilayers with local reorientation of the bilayer phospholipids.

---

Organizational Affiliation: 
• Stanford Synchrotron Radiation Laboratory, California 94305, USA.

Biological Assembly 1  

Global Symmetry: Dihedral - D3  (Explore in 3D)
Global Stoichiometry: Homo 6-mer - A6 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content 

• Total Structure Weight: 211.11 kDa 
• Atom Count: 14,796 
• Modeled Residue Count: 1,890 
• Deposited Residue Count: 1,890 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
ANNEXIN XII	A, B, C, D, E, F	315	Hydra vulgaris	Mutation(s): 0
UniProt
Find proteins for P26256 (Hydra vulgaris) Explore P26256  Go to UniProtKB:  P26256

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
CA	AA [auth F], BA [auth F], CA [auth F], DA [auth F], G [auth A], H [auth A], I [auth A], J [auth A], K [auth B], L [auth B], M [auth B], N [auth B], O [auth C], P [auth C], Q [auth C], R [auth C], S [auth D], T [auth D], U [auth D], V [auth D], W [auth E], X [auth E], Y [auth E], Z [auth E]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Free:  0.278 (Depositor) 
• R-Value Work:  0.236 (Depositor) 
• R-Value Observed: 0.236 (Depositor) 

Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 71.2	α = 90
b = 179.2	β = 97.6
c = 100.7	γ = 90

Software Package:

Software Name	Purpose
GLRF	phasing
X-PLOR	model building
X-PLOR	refinement
MOSFLM	data reduction
CCP4	data scaling
ROTAVATA	data scaling
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 1997-08-20 
Deposition Author(s): Luecke, H., Chang, B.T., Mailliard, W.S., Schlaepfer, D.D., Haigler, H.T.

Revision History  

• Version 1.0: 1997-08-20
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2024-02-07
  Changes: Data collection, Database references, Derived calculations, Refinement description
• Version 1.4: 2024-04-03
  Changes: Refinement description