2NV3

Solution structure of L8A mutant of HIV-1 myristoylated matrix protein

Summary for 2NV3

• Entry DOI: 10.2210/pdb2nv3/pdb
• Related: 2H3I 2JMG
• Descriptor: Gag polyprotein, MYRISTIC ACID (2 entities in total)
• Functional Keywords: l8a mutant of hiv-1 myristoylated matrix protein, viral protein
• Biological source: Human immunodeficiency virus 1
• Cellular location: Matrix protein p17: Virion (By similarity): Q72497
• Total number of polymer chains: 1
• Total formula weight: 14920.90

Authors

Saad, J.S.,Loeliger, E.,Luncsford, P.,Liriano, M.,Tai, J.,Kim, A.,Miller, J.,Joshi, A.,Freed, E.O.,Summers, M.F. (deposition date: 2006-11-10, release date: 2007-02-06, Last modification date: 2024-10-30)

Primary citation

Saad, J.S.,Loeliger, E.,Luncsford, P.,Liriano, M.,Tai, J.,Kim, A.,Miller, J.,Joshi, A.,Freed, E.O.,Summers, M.F.
Point mutations in the HIV-1 matrix protein turn off the myristyl switch.
J.Mol.Biol., 366:574-585, 2007

PubMed Abstract: During the late phase of human immunodeficiency virus type-1 (HIV-1) replication, newly synthesized retroviral Gag proteins are targeted to lipid raft regions of specific cellular membranes, where they assemble and bud to form new virus particles. Gag binds preferentially to the plasma membrane (PM) of most hematopoietic cell types, a process mediated by interactions between the cellular PM marker phosphatidylinositol-(4,5)-bisphosphate (PI(4,5)P(2)) and Gag's N-terminally myristoylated matrix (MA) domain. We recently demonstrated that PI(4,5)P(2) binds to a conserved cleft on MA and promotes myristate exposure, suggesting a role as both a direct membrane anchor and myristyl switch trigger. Here we show that PI(4,5)P(2) is also capable of binding to MA proteins containing point mutations that inhibit membrane binding in vitro, and in vivo, including V7R, L8A and L8I. However, these mutants do not exhibit PI(4,5)P(2) or concentration-dependent myristate exposure. NMR studies of V7R and L8A MA reveal minor structural changes that appear to be responsible for stabilizing the myristate-sequestered (myr(s)) species and inhibiting exposure. Unexpectedly, the myristyl group of a revertant mutant with normal PM targeting properties (V7R,L21K) is also tightly sequestered and insensitive to PI(4,5)P(2) binding. This mutant binds PI(4,5)P(2) with twofold higher affinity compared with the native protein, suggesting a potential compensatory mechanism for membrane binding.

PubMed: 17188710
DOI: 10.1016/j.jmb.2006.11.068

Experimental method

SOLUTION NMR