1UPH

HIV-1 Myristoylated Matrix


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: LOWEST TARGET FUNCTION 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Entropic Switch Regulates Myristate Exposure in the HIV-1 Matrix Protein

Tang, C.Loeliger, E.Luncsford, P.Kinde, I.Beckett, D.Summers, M.F.

(2004) Proc Natl Acad Sci U S A 101: 517

  • DOI: 10.1073/pnas.0305665101
  • Primary Citation of Related Structures:  
    1UPH

  • PubMed Abstract: 
  • The myristoylated matrix protein (myr-MA) of HIV functions as a regulator of intracellular localization, targeting the Gag precursor polyprotein to lipid rafts in the plasma membrane during virus assembly and dissociating from the membrane during inf ...

    The myristoylated matrix protein (myr-MA) of HIV functions as a regulator of intracellular localization, targeting the Gag precursor polyprotein to lipid rafts in the plasma membrane during virus assembly and dissociating from the membrane during infectivity for nuclear targeting of the preintegration complex. Membrane release is triggered by proteolytic cleavage of Gag, and it has, until now, been believed that proteolysis induces a conformational change in myr-MA that sequesters the myristyl group. NMR studies reported here reveal that myr-MA adopts myr-exposed [myr(e)] and -sequestered [myr(s)] states, as anticipated. Unexpectedly, the tertiary structures of the protein in both states are very similar, with the sequestered myristyl group occupying a cavity that requires only minor conformational adjustments for insertion. In addition, myristate exposure is coupled with trimerization, with the myristyl group sequestered in the monomer and exposed in the trimer (K(assoc) = 2.5 +/- 0.6 x 10(8) M(-2)). The equilibrium constant is shifted approximately 20-fold toward the trimeric, myristate-exposed species in a Gag-like construct that includes the capsid domain, indicating that exposure is enhanced by Gag subdomains that promote self-association. Our findings indicate that the HIV-1 myristyl switch is regulated not by mechanically induced conformational changes, as observed for other myristyl switches, but instead by entropic modulation of a preexisting equilibrium.


    Organizational Affiliation

    Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250-5398, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
GAG POLYPROTEINA132Human immunodeficiency virus type 1 (CLONE 12)Mutation(s): 0 
EC: 3.4.23.16 (UniProt), 2.7.7.49 (UniProt), 2.7.7.7 (UniProt), 3.1.26.13 (UniProt), 3.1.13.2 (UniProt), 2.7.7 (UniProt), 3.1 (UniProt)
Find proteins for P12497 (Human immunodeficiency virus type 1 group M subtype B (isolate NY5))
Explore P12497 
Go to UniProtKB:  P12497
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: LOWEST TARGET FUNCTION 
  • OLDERADO: 1UPH Olderado

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-01-08
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance