PDBsum entry 2mgu

Protein binding

PDB id: 2mgu

Contents

Protein chains

148 a.a.

36 a.a.

Metals

_CA ×4

PDB id:

2mgu

Name:

Protein binding

Title:

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

Structure:

Calmodulin. Chain: a. Synonym: cam. Engineered: yes. Ma8-43. Chain: m. Engineered: yes

Source:

Rattus norvegicus. Brown rat,rat,rats. Organism_taxid: 10116. Gene: calm1, calm, cam, cam1, calm2, cam2, camb, calm3, cam3, camc. Expressed in: escherichia coli. Expression_system_taxid: 562. Human immunodeficiency virus 1. Organism_taxid: 11676. Gene: gag.

NMR struc:

20 models

Authors:

J.Vlach,A.Samal,J.Saad

Key ref:

J.Vlach et al. (2014). Solution structure of calmodulin bound to the binding domain of the HIV-1 matrix protein. J Biol Chem, 289, 8697-8705. PubMed id: 24500712 DOI: 10.1074/jbc.M113.543694

Date:

07-Nov-13 Release date: 12-Feb-14

Protein chain

P0DP29  (CALM1_RAT) -  Calmodulin-1 from Rattus norvegicus

Seq: 149 a.a.

Struc: 148 a.a.

Protein chain

P12493  (GAG_HV1N5) -  Gag polyprotein from Human immunodeficiency virus type 1 group M subtype B (isolate NY5)

Seq: 500 a.a.

Struc: 36 a.a.

DOI no: 10.1074/jbc.M113.543694

J Biol Chem 289:8697-8705 (2014)

PubMed id: 24500712

Solution structure of calmodulin bound to the binding domain of the HIV-1 matrix protein.

J.Vlach, A.B.Samal, J.S.Saad.

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.