Question

Brief about the viral proteins.

Answer 1

Viral proteins:

1. Viruses are acellular organisms that cannot replicate outside the host cell.
2. The proteins generated by viruses can be classified into four categories- core proteins, envelope proteins, viral enzymes, and nucleocapsid proteins.
3. Core proteins play a vital role in virion assembly and interaction with numerous host cell proteins.
4. Envelope proteins are glycoproteins that are found in enveloped viruses (eg., retrovirus). These proteins help the virus in binding to the host cell and mediate the fusion of viral and cellular membranes.
5. The enveloped viruses possess enzymes such as reverse transcriptase and integrase. Reverse transcriptase helps to convert RNA to DNA, whereas, integrase helps to incorporate the viral genome into the host cell.
6. Some viruses such as TMV have nucleocapsid (a combination of capsid and nucleic acid). The capsid proteins of these viruses are made up of identical protein subunits.