Mikrovirus

Mikrovirus is a genus of small, isometric viruses belonging to the family Microviridae. These viruses infect bacteria, specifically Gram-negative bacteria. The virion, or virus particle, is non-enveloped and has an icosahedral capsid. The genome of mikroviruses consists of single-stranded DNA (ssDNA).

The most well-known member of this genus is the bacteriophage Phi X 174 (often written as φX174). This phage was historically significant in molecular biology research and was the first virus to have its entire genome sequenced. The genome of Phi X 174 is small, encoding a limited number of proteins essential for replication and assembly of new virions.

Replication of mikroviruses occurs within the bacterial cytoplasm. Upon infection, the viral ssDNA genome is converted into a double-stranded replicative form (RF) DNA. This RF DNA then serves as a template for the synthesis of new ssDNA genomes and for the production of viral proteins. Mature virions are assembled within the host cell and are released upon lysis of the bacterium.

Mikroviruses are relatively simple viruses and have been valuable tools for understanding fundamental biological processes, particularly in the early days of molecular genetics. Their small genome size and relatively straightforward replication cycle made them amenable to study.