What is slippage during DNA replication?
Replication slippage or slipped-strand mispairing involves the misalignment of DNA strands during the replication of repeated DNA sequences, and can lead to genetic rearrangements such as microsatellite instability.
Why does slippage in a template strand cause a deletion?
The nascent and template strands can disassociate and then reanneal; during this process the strands can slip such that the repeat sequences are not properly aligned. Subsequent replication results in deletion or addition of a repeat, depending on whether the template or nascent strand is misaligned upon reannealing.
On what type of region does DNA polymerase slippage usually occur?
Insertions and Deletions (Indels) Polymerase slippage classically affects DNA regions with direct (also referred to as tandem) repeats of 1–4 bases (e.g., [T]n or [AGGC]n, with n number of repeats) and results in insertion of only one or two additional repeats .
What is a slipped structure?
Slipped strand DNA structures are formed when complementary strands comprising direct repeats pair in a misaligned, or slipped, fashion along the DNA helix axis.
What is a strand slippage?
From Wikipedia, the free encyclopedia. Slipped strand mispairing (SSM), (also known as replication slippage), is a mutation process which occurs during DNA replication. It involves denaturation and displacement of the DNA strands, resulting in mispairing of the complementary bases.
How does strand slippage occur?
Strand slippage occurs by mispairing of the template strand and the newly synthesized strand during DNA replication.
Why does DNA polymerase slippage occur?
A slippage event normally occurs when a sequence of repetitive nucleotides (tandem repeats) are found at the site of replication. When DNA polymerase encounters a direct repeat, it can undergo a replication slippage. Strand slippage may also occur during the DNA synthesis step of DNA repair processes.
What happens during strand slippage?
Slipped strand mispairing (SSM), (also known as replication slippage), is a mutation process which occurs during DNA replication. It involves denaturation and displacement of the DNA strands, resulting in mispairing of the complementary bases.
What is Depurination of DNA?
Depurination involves the loss of purine bases (adenine and guanine) from DNA. In spontaneously occurring depurination reactions, the N-glycosyl bound to deoxyribose is broken by hydrolysis, leaving the DNA’s sugar–phosphate chain intact, producing an abasic site.
What is slippage error?
Replication slippage is a particular type of error caused by DNA polymerases believed to occur both in bacterial and eukaryotic cells. Previous studies have shown that deletion events can occur in Escherichia coli by replication slippage between short duplications and that the main E.
What is DNA Mispairing?
During DNA replication slipped-strand mispairing occurs when the nascent DNA strand temporarily dissociates from the template strand and then re-anneals such that the repeats on the two strands are out of register.