What is tautomeric shift in DNA?

The spontaneous isomerization of a nitrogen base to an alternative hydrogen-bonding form, possibly resulting in a mutation. Reversible shifts of proton position in a molecule. bases in nucleic acids shift between keto and enol forms or between amino and imino forms.

Do tautomeric shifts cause point mutations?

Tautomeric shifts that modify the pairing of nucleotides can result in base substitutions and, as a result, mutations. Tautomeric forms of DNA bases.

What kind of mutations do tautomeric shifts cause?

A tautomeric shift in one strand has produced a transition mutation in the complementary strand. If the mutation occurs in the germline, it will be transmitted to future generations. IMPORTANT: Note that a tautomeric shift is not itself a mutation, but a transient change to an alternative form of the molecule.

Which types of mutations arise due to a tautomeric shift in nitrogenous bases of DNA?

A point mutation is a change in a single base pair location. There are several types: transition mutation – change of one purine/pyrimidine pair to the other purine/pyrimidine pair. This can happen when one base member of a complementary pair undergoes a tautomeric shift during DNA replication, causing it to mispair.

What causes DNA tautomerization?

An error in DNA replication can occur when an illegitimate nucleotide pair (say, A–C) forms in DNA synthesis, leading to a base substitution. Each of the bases in DNA can appear in one of several forms, called tautomers, which are isomers that differ in the positions of their atoms and in the bonds between the atoms.

How do Deaminating agents cause mutations?

Deamination of adenine results in the formation of hypoxanthine. Hypoxanthine, in a manner analogous to the imine tautomer of adenine, selectively base pairs with cytosine instead of thymine. This results in a post-replicative transition mutation, where the original A-T base pair transforms into a G-C base pair.

What are the 6 types of mutations?

What kinds of gene variants are possible?

Missense. A missense variant is a type of substitution in which the nucleotide change results in the replacement of one protein building block (amino acid) with another in the protein made from the gene.
Nonsense.
Insertion.
Deletion.
Duplication.
Frameshift.
Repeat expansion.

What is tautomeric shift in DNA? The spontaneous isomerization of a nitrogen base to an alternative hydrogen-bonding form, possibly resulting in a mutation. Reversible shifts of proton position in a molecule. bases in nucleic acids shift between keto and enol forms or between amino and imino forms. Do tautomeric shifts cause point mutations? Tautomeric shifts…