Chemistry Reference
In-Depth Information
Figure 6.6
Mechanism of translesion synthesis in mammalian cells
mechanisms of DNA repair, which may cause gross chromosomal aberrations or
cell death. Cells use both transcriptional and posttranslational regulation to keep
these low - fi delity polymerases under strict control and limit their access to a replica-
tion fork.
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Lesion bypass directly utilizes the damaged template. Conceptually, lesion
bypass can be divided into two steps: (i) nucleotide incorporation opposite the lesion
(i.e., translesion synthesis), followed by (ii) extension of DNA synthesis. After a
short stretch of extension, normal DNA synthesis by the replication apparatus can
then resume. Signifi cantly, lesion bypass can be either error-free, whereby the correct
