7m1w

From Proteopedia

NMR structure of the Human T-cell leukemia virus 1 matrix protein

Structural highlights

7m1w is a 1 chain structure with sequence from Human T-cell leukemia virus type I. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance.
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

Q9QR99_9DELA

Publication Abstract from PubMed

Retroviral Gag targeting to the plasma membrane (PM) for assembly is mediated by the N-terminal matrix (MA) domain. For many retroviruses, Gag-PM interaction is dependent on phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). However, it has been shown that for human T-cell leukemia virus type 1 (HTLV-1), Gag binding to membranes is less dependent on PI(4,5)P2 than HIV-1, suggesting that other factors may modulate Gag assembly. To elucidate the mechanism by which HTLV-1 Gag binds to the PM, we employed NMR techniques to determine the structure of unmyristoylated MA (myr(-)MA) and to characterize its interactions with lipids and liposomes. The MA structure consists of four alpha-helices and unstructured N- and C-termini. We show that myr(-)MA binds to PI(4,5)P2 via the polar head and that binding to inositol phosphates (IPs) is significantly enhanced by increasing the number of phosphate groups on the inositol ring, indicating that the MA-IP binding is governed by charge-charge interactions. The IP binding site was mapped to a well-defined basic patch formed by lysine and arginine residues. Using an NMR-based liposome binding assay, we show that PI(4,5)P2and phosphatidylserine enhance myr(-)MA binding in a synergistic fashion. Confocal microscopy data revealed formation of puncta on the PM of Gag expressing cells. However, G2A-Gag mutant, lacking myristoylation, is diffuse and cytoplasmic. These results suggest that although myr(-)MA binds to membranes, myristoylation appears to be key for formation of HTLV-1 Gag puncta on the PM. Altogether, these findings advance our understanding of a key mechanism in retroviral assembly.

Structural Insights into the Mechanism of Human T-cell Leukemia Virus Type 1 Gag Targeting to the Plasma Membrane for Assembly.,Herrmann D, Zhou LW, Hanson HM, Willkomm NA, Mansky LM, Saad JS J Mol Biol. 2021 Sep 17;433(19):167161. doi: 10.1016/j.jmb.2021.167161. Epub 2021, Jul 21. PMID:34298060^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Herrmann D, Zhou LW, Hanson HM, Willkomm NA, Mansky LM, Saad JS. Structural Insights into the Mechanism of Human T-cell Leukemia Virus Type 1 Gag Targeting to the Plasma Membrane for Assembly. J Mol Biol. 2021 Sep 17;433(19):167161. PMID:34298060 doi:10.1016/j.jmb.2021.167161