View source for 1uph

[[Image:1uph.gif|left|200px]]

 {{Structure
|PDB= 1uph |SIZE=350|CAPTION= <scene name='initialview01'>1uph</scene>
|SITE= 
|LIGAND= <scene name='pdbligand=MYR:MYRISTIC+ACID'>MYR</scene>
|ACTIVITY= 
|GENE= 
|DOMAIN=
|RELATEDENTRY=
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1uph FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1uph OCA], [http://www.ebi.ac.uk/pdbsum/1uph PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1uph RCSB]</span>
}}

'''HIV-1 MYRISTOYLATED MATRIX'''


==Overview==
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.

==About this Structure==
1UPH is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Human_immunodeficiency_virus_type_1_(isolate_12) Human immunodeficiency virus type 1 (isolate 12)]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1UPH OCA]. 

==Reference==
Entropic switch regulates myristate exposure in the HIV-1 matrix protein., Tang C, Loeliger E, Luncsford P, Kinde I, Beckett D, Summers MF, Proc Natl Acad Sci U S A. 2004 Jan 13;101(2):517-22. Epub 2003 Dec 29. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/14699046 14699046]
[[Category: Human immunodeficiency virus type 1 (isolate 12)]]
[[Category: Single protein]]
[[Category: Beckett, D.]]
[[Category: Kinde, I.]]
[[Category: Loeliger, E.]]
[[Category: Luncsford, P.]]
[[Category: Summers, M F.]]
[[Category: Tang, C.]]
[[Category: myristoylated]]
[[Category: myristyl]]
[[Category: myristyl switch]]
[[Category: phosphorylation]]
[[Category: polyprotein]]
[[Category: post-translational modification]]

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