Year: 2013
Type: review
Abstract: Simple DNA repeats (trinucleotide repeats, micro- and minisatellites) are prone to expansion/contraction via formation of secondary structures during DNA synthesis. Such structures both inhibit replication forks and create opportunities for template-primer slippage, making these repeats unstable. Certain aspects of simple repeat instability, however, suggest additional mechanisms of replication inhibition dependent on the primary DNA sequence, rather than on secondary structure formation. I argue that expanded simple repeats, due to their lower DNA complexity, should transiently inhibit DNA synthesis by locally depleting specific DNA precursors. Such transient inhibition would promote formation of secondary structures and would stabilize these structures, facilitating strand slippage. Thus, replication problems at simple repeats could be explained by potentiated toxicity, where the secondary structure-driven repeat instability is enhanced by DNA polymerase stalling at the low complexity template DNA.
Source: BioEssays
Author: Andrei Kuzminov
Institution: University of Illinois Urbana-Champaign
Language: English
Topic: DNA Repair Mechanisms
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2089005649