How do RNA and DNA viruses differ?

DNA viruses

Viruses differ, among other things, in the form of their genetic material, i.e. the genetic information of the virus. In the case of DNA viruses, the genetic material consists of DNA, i.e. deoxyribonucleic acid, according to the name. The virus DNA contains the blueprint for the virus particle and enables the virus to multiply in host cells.

DNA viruses protect the genetic material with a protein capsule, the so-called Capsid. The DNA can exist there in different forms: as Double strand or as Single strand. Scientists use this difference among other criteria to assign DNA viruses to different virus families.

The DNA viruses include researchers over 20 Virus families, among the most important are:

In addition to the shape of the DNA, other classification criteria play a role, such as the shape or symmetry of the capsid or whether the capsid is additionally surrounded by a shell. For example, many DNA virus capsids have one cubic symmetry, i.e. the shape of a multi-faceted cube (lat. cubus = Cube): Often the capsid shape resembles one Icosahedron (= Twenty surfaces). Other capsids have a so-called complex symmetry, that is, they do not show any clear symmetry, but still have a regular shape (e.g. smallpox viruses).

Virus familyCapsid shapeShellDNA
Parvovirusescubicnakedsingle-stranded
Papillomavirusescubicnakeddouble-stranded
Adenovirusescubicnakeddouble-stranded
HepadnavirusescubicShellsingle / double stranded
Herpes virusescubicShelldouble-stranded
Smallpox virusescomplexShelldouble-stranded

In contrast to RNA viruses, in which the genetic material is in the form of RNA (ribonucleic acid), the genetic material of DNA viruses is clear due to the chemical structure more stable. In comparison, changes in the genetic material (mutations) occur less frequently with DNA viruses.

In addition, DNA viruses benefit from something else: Like RNA viruses, DNA viruses use the cell machinery of the infected cell to multiply. Many DNA viruses can benefit from a special enzyme in the host cell: the DNA polymerase, a kind of correction unit of the cell. It can recognize and remove incorrectly built-in building blocks of DNA (nucleotides). As a result, fewer errors creep into the genetic make-up when the DNA viruses multiply and mutations occur less frequently.

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