encapsidates

Encapsidates refers to viral genomes that have been enclosed by a protein capsid to form a virion. Encapsidation is the process by which capsid proteins assemble around the nucleic acid, producing a stable particle that protects the genome and enables transmission to a new host cell. In most viruses the genome is either DNA or RNA and is packaged inside a protein shell; enveloped viruses have this nucleocapsid surrounded by a lipid envelope, while non-enveloped viruses consist only of the capsid and genome.

The encapsidation process relies on sequence- or structure-specific signals in the genome that are recognized by capsid proteins or assembly factors, ensuring selective packaging and correct genome length. Some viruses assemble a preformed capsid that later encases the genome, while others package the genome as the shell forms. Packaging efficiency and fidelity influence infectivity and particle stability; mispackaged or defective particles are typically noninfectious.

Encapsidated virions are generally robust, protecting the genome from nucleases and environmental stress and facilitating transmission between hosts. Infection usually proceeds via attachment to a receptor, entry into the cell, and uncoating to release the genome from the capsid. Studying encapsidation informs understanding of viral assembly, host specificity, and antiviral targets.

Encapsidates can be distinguished from naked nucleic acids or non-encapsidated components. The concept applies across many DNA and RNA viruses and their progeny particles. See also: capsid, virion, encapsidation.