What mutation does 5-bromouracil cause?
5-Bromouracil (BrU) is a base analogue of thymine (T) which can be incorporated into DNA. It is a well-known mutagen, causing transition mutations by mispairing with guanine (G) rather than pairing with adenine (A) during replication.
What are base analog mutagens?
Base analogs are derivatives of the normal DNA bases, which may mimic to varying extents the properties of the normal bases. As such, they have the ability to interfere with normal nucleotide metabolism and exert a variety of toxic and mutagenic effects.
What happens with 5-bromouracil is added to a wild type DNA molecule?
If 5-BU is incorporated into DNA in place of thymine, the tautomeric shift will occur, and the 5-BU will base pair with guanine. After the replication, an A-T to G-C transition occurs. Furthermore, the presence of 5-BU within DNA increases the sensitivity of the molecule to UV light.
What kind of mutations do base analogs cause?
Base Analogs That Alter Base Pairing Preference During subsequent replication, this causes AT-to-GC transition mutations. 2-AP is an adenine analog and it usually pairs with thymine, but it can also form pairs with cytosine, causing both AT-to-GC and GC-to-AT transition mutations.
What are base analogues give example and the type of their action?
any chemical that has a similar structure (i.e. is analogous) to one of the purine or pyrimidine bases in DNA or RNA. Such analogues can become incorporated into the nucleic acid and may act as a MUTAGEN. For example, 5-bromouracil (5Bu) is an analogue of thymine and can be incorporated into DNA in place of thymine.
Is 5-Bromouracil carcinogenic?
Laboratory chemical used as a mutagen in many mutagenesis experiments. 5-bromouracil is a mutagen (causes mutations) and a carcinogen.
What do you understand by base analogues?
Base analogue. (Science: biochemistry) a chemical which resembles a nucleotide base. They can substitute the purine and pyrimidine bases that normally appear in dna, despite minor differences in structure. May be used for inducing mutations, including point mutations.
How are base analogs repaired?
Base-analog DNA cycle. When cleansing is inefficient, base-analogs are incorporated into DNA. Damaged bases lead to mutations in replication cycles or can be correctly repaired by base excision repair. Intermediates of this repair can lead to mutagenesis, DNA breaks, and chromosome changes.