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High-resolution structure of a retroviral capsid hexameric amino-terminal domain

An Erratum to this article was published on 21 October 2004


Retroviruses are the aetiological agents of a range of human diseases including AIDS and T-cell leukaemias. They follow complex life cycles, which are still only partly understood at the molecular level. Maturation of newly formed retroviral particles is an essential step in production of infectious virions, and requires proteolytic cleavage of Gag polyproteins in the immature particle to form the matrix, capsid and nucleocapsid proteins present in the mature virion1. Capsid proteins associate to form a dense viral core2 that may be spherical, cylindrical or conical depending on the genus of the virus3. Nonetheless, these assemblies all appear to be composed of a lattice formed from hexagonal rings, each containing six capsid monomers2,4,5. Here, we describe the X-ray structure of an individual hexagonal assembly from N-tropic murine leukaemia virus (N-MLV). The interface between capsid monomers is generally polar, consistent with weak interactions within the hexamer. Similar architectures are probably crucial for the regulation of capsid assembly and disassembly in all retroviruses. Together, these observations provide new insights into retroviral uncoating and how cellular restriction factors may interfere with viral replication.

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Figure 1: The structure of the NTD of N-MLV capsid.
Figure 2: The structure of N-MLV NTD hexameric assembly.
Figure 3: Details of the molecular interactions between monomers at the interface.
Figure 4: Interactions mediated by residues located on or around the β1–β2 hairpin.


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We thank S. Gamblin for assistance in crystal handling.

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Correspondence to Ian A. Taylor.

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Mortuza, G., Haire, L., Stevens, A. et al. High-resolution structure of a retroviral capsid hexameric amino-terminal domain. Nature 431, 481–485 (2004).

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