nucleokapsid

Nucleokapsid is a term used in virology to describe the complex formed by viral genetic material and the proteins that encapsulate it. This genetic material can be DNA or RNA, and it is always enclosed within a protein shell known as the capsid. The capsid itself is made up of repeating subunits called capsomeres. Together, the nucleic acid and the capsid constitute the nucleokapsid. In some viruses, the nucleokapsid is further surrounded by a lipid envelope derived from the host cell membrane. However, the nucleokapsid is a fundamental structural component present in all viruses. The specific arrangement and composition of the nucleokapsid vary greatly between different virus families, contributing to their classification and identification. The nucleokapsid plays a crucial role in viral replication, protecting the viral genome from degradation and facilitating its entry into host cells.