Biological Assembly 1  

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

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 21.20 kDa 
• Atom Count: 1473 
• Modelled Residue Count: 184 
• Deposited Residue Count: 184 
• Unique protein chains: 2

2MGU

Structure of the complex between calmodulin and the binding domain of HIV-1 matrix protein

• PDB DOI: 10.2210/pdb2MGU/pdb
• BMRB: 19604

• Classification: PROTEIN BINDING
• Organism(s): Rattus norvegicus, Human immunodeficiency virus 1
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2013-11-07 Released: 2014-02-12 
• Deposition Author(s): Vlach, J., Samal, A., Saad, J.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 20 
• Selection Criteria: target function 

Literature

Solution Structure of Calmodulin Bound to the Binding Domain of the HIV-1 Matrix Protein.

Vlach, J., Samal, A.B., Saad, J.S.

(2014) J Biol Chem 289: 8697-8705

• PubMed: 24500712 
• DOI: 10.1074/jbc.M113.543694
• Primary Citation of Related Structures:  
  2MGU


• PubMed Abstract: 
  

Subcellular distribution of calmodulin (CaM) in human immunodeficiency virus type-1 (HIV-1)-infected cells is distinct from that observed in uninfected cells. CaM co-localizes and interacts with the HIV-1 Gag protein in the cytosol of infected cells. Although it has been shown that binding of Gag to CaM is mediated by the matrix (MA) domain, the structural details of this interaction are not known. We have recently shown that binding of CaM to MA induces a conformational change that triggers myristate exposure, and that the CaM-binding domain of MA is confined to a region spanning residues 8-43 (MA-(8-43)). Here, we present the NMR structure of CaM bound to MA-(8-43). Our data revealed that MA-(8-43), which contains a novel CaM-binding motif, binds to CaM in an antiparallel mode with the N-terminal helix (α1) anchored to the CaM C-terminal lobe, and the C-terminal helix (α2) of MA-(8-43) bound to the N-terminal lobe of CaM. The CaM protein preserves a semiextended conformation. Binding of MA-(8-43) to CaM is mediated by numerous hydrophobic interactions and stabilized by favorable electrostatic contacts. Our structural data are consistent with the findings that CaM induces unfolding of the MA protein to have access to helices α1 and α2. It is noteworthy that several MA residues involved in CaM binding have been previously implicated in membrane binding, envelope incorporation, and particle production. The present findings may ultimately help in identification of the functional role of CaM in HIV-1 replication.

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Organizational Affiliation: 

From the Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Calmodulin	A	148	Rattus norvegicus	Mutation(s): 0  Gene Names:  Calm1, Calm, Cam, Cam1, Calm2, Cam2, Camb, Calm3, Cam3, Camc, CaMI
UniProt
Find proteins for P0DP29 (Rattus norvegicus) Explore P0DP29  Go to UniProtKB:  P0DP29

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
MA8-43	B [auth M]	36	Human immunodeficiency virus 1	Mutation(s): 0  Gene Names: gag
UniProt
Find proteins for P12493 (Human immunodeficiency virus type 1 group M subtype B (isolate NY5)) Explore P12493  Go to UniProtKB:  P12493

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
CA	C [auth A], D [auth A], E [auth A], F [auth A]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 20 
• Selection Criteria: target function 
• OLDERADO: 2MGU Olderado

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2013-11-07 
• Released Date: 2014-02-12 
Deposition Author(s): Vlach, J., Samal, A., Saad, J.

Revision History  

• Version 1.0: 2014-02-12
  Type: Initial release
  
• Version 1.1: 2014-05-07
  Changes: Database references