1HG2

CALM-N N-terminal domain of clathrin assembly lymphoid myeloid leukaemia protein, Inositol(4,5)P2 complex

• PDB DOI: https://doi.org/10.2210/pdb1HG2/pdb

• Classification: ENDOCYTOSIS
• Organism(s): Rattus norvegicus
• Expression System: Escherichia coli BL21
• Mutation(s): No 


• Deposited: 2000-12-12 Released: 2001-02-12 
• Deposition Author(s): Ford, M.G.J., Evans, P.R., McMahon, H.T.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Free: 0.217 
• R-Value Work: 0.197 
• R-Value Observed: 0.198 

Literature

Simultaneous Binding of Ptdins(4,5)P2 and Clathrin by Ap180 in the Nucleation of Clathrin Lattices on Membranes

Ford, M.G.J., Pearse, B.M.F., Higgins, M.K., Vallis, Y., Owen, D.J., Gibson, A., Hopkins, C.R., Evans, P.R., Mcmahon, H.T.

(2001) Science 291: 1051

• PubMed: 11161218 
• DOI: https://doi.org/10.1126/science.291.5506.1051
• Primary Citation of Related Structures:  
  1HF8, 1HFA, 1HG2, 1HG5


• PubMed Abstract: 
  

  Adaptor protein 180 (AP180) and its homolog, clathrin assembly lymphoid myeloid leukemia protein (CALM), are closely related proteins that play important roles in clathrin-mediated endocytosis. Here, we present the structure of the NH2-terminal domain of CALM bound to phosphatidylinositol-4,5- bisphosphate [PtdIns(4,5)P2] via a lysine-rich motif. This motif is found in other proteins predicted to have domains of similar structure (for example, Huntingtin interacting protein 1). The structure is in part similar to the epsin NH2-terminal (ENTH) domain, but epsin lacks the PtdIns(4,5)P2-binding site. Because AP180 could bind to PtdIns(4,5)P2 and clathrin simultaneously, it may serve to tether clathrin to the membrane. This was shown by using purified components and a budding assay on preformed lipid monolayers. In the presence of AP180, clathrin lattices formed on the monolayer. When AP2 was also present, coated pits were formed.

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Organizational Affiliation: 

Medical Research Council (MRC) Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 2QH, UK.

Biological Assembly 1  

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

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

Macromolecule Content

• Total Structure Weight: 33.21 kDa 
• Atom Count: 2,282 
• Modelled Residue Count: 263 
• Deposited Residue Count: 289 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
CLATHRIN ASSEMBLY PROTEIN SHORT FORM	A	289	Rattus norvegicus	Mutation(s): 0
UniProt
Find proteins for O55012 (Rattus norvegicus) Explore O55012  Go to UniProtKB:  O55012

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
IP2	B [auth A]	D-MYO-INOSITOL-4,5-BISPHOSPHATE C6 H14 O12 P2 MCKAJXMRULSUKI-UZAAGFTCSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Free: 0.217 
• R-Value Work: 0.197 
• R-Value Observed: 0.198 
• Space Group: P 4₁ 2₁ 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 77.859	α = 90
b = 77.859	β = 90
c = 122.333	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
MOSFLM	data reduction
SCALA	data scaling

Structure Validation

Entry History 

Deposition Data

• Released Date: 2001-02-12 
Deposition Author(s): Ford, M.G.J., Evans, P.R., McMahon, H.T.

Revision History  

• Version 1.0: 2001-02-12
  Type: Initial release
  
• Version 1.1: 2011-05-08
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2019-10-09
  Changes: Data collection, Experimental preparation, Other
• Version 1.4: 2023-12-13
  Changes: Data collection, Database references, Refinement description