{
  "id": 6239083,
  "title": "MxB N-Terminus Adopts a Stable α-Helix to Engage the HIV-1 Capsid Trimer Interface",
  "url": "https://urgent.news/2026/09/07/mxb-n-terminus-adopts-a-stable-helix-to-engage-the-hiv-1-capsid",
  "topic": "health",
  "section": "Health & Medicine",
  "published": "2026-09-07T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.09.03.749210v1?rss=1"
  },
  "original_language": "en",
  "account": "The HIV-1 capsid, made up of CA proteins arranged in a conical shape, plays a crucial role in host-pathogen interactions. Certain host factors, like Myxovirus resistance protein B (MxB), help control HIV-1 infection by recognizing the larger CA lattice instead of individual proteins. MxB binds to the capsid through its N-terminal part, which contains a series of arginine residues (RRR). This binding prevents HIV-1 infection at the very beginning of the infection. So far, scientists have not understood how MxB interacts with the capsid. In this research, a detailed look at the CA lattice interacting with the MxB N-terminal fragment was done using a technique called cryo-electron tomography and averaging of small pieces of images. By combining these electron microscope structures with computer simulations, researchers have found specific places where MxB's N-terminal part connects with the CA trimer interfaces. Most importantly, they discovered that residues 10-20 in the MxB N-terminal part make an alpha-helical structure that helps bind the CA trimer interface. This is a new way for the capsid to be engaged. These discoveries give us a better understanding of how MxB and other cell helpers recognize the capsid and lay the foundation for making new medicines that target the capsid.",
  "summary": "The HIV-1 capsid, composed of capsid (CA) proteins arranged into a conical surface lattice, serves as a critical platform for host-pathogen interactions. Many host cofactors regulate HIV-1 infection by selectively recognizing the higher-order CA lattice rather than individual monomers or capsomers. Among these, Myxovirus resistance protein B (MxB) is a key cellular restriction factor that binds…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}