Transversion
Encyclopedia
In molecular biology
, transversion refers to the substitution of a purine
for a pyrimidine
or vice versa. It can only be reverted by a spontaneous reversion. Because this type of mutation
changes the chemical structure dramatically, the consequences of this change tend to be more drastic than those of transitions
. Transversions can be caused by ionizing radiation and alkylating agents.
Molecular biology
Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...
, transversion refers to the substitution of a purine
Purine
A purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. Purines, including substituted purines and their tautomers, are the most widely distributed kind of nitrogen-containing heterocycle in nature....
for a pyrimidine
Pyrimidine
Pyrimidine is a heterocyclic aromatic organic compound similar to benzene and pyridine, containing two nitrogen atoms at positions 1 and 3 of the six-member ring...
or vice versa. It can only be reverted by a spontaneous reversion. Because this type of mutation
Mutation
In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...
changes the chemical structure dramatically, the consequences of this change tend to be more drastic than those of transitions
Transition (genetics)
In genetics, a transition is a point mutation that changes a purine nucleotide to another purine or a pyrimidine nucleotide to another pyrimidine . Approximately two out of three single nucleotide polymorphisms are transitions....
. Transversions can be caused by ionizing radiation and alkylating agents.