Crosslinking of DNA
In genetics, crosslinking of DNA occurs when various exogenous or endogenous agents react with two different positions in the DNA. This can either occur in the same strand (intrastrand crosslink) or in the opposite strands of the DNA (interstrand crosslink). Crosslinks also occur between DNA and protein. DNA replication is blocked by crosslinks, which causes replication arrest and cell death if the crosslink is not repaired.
The RAD51 family plays a role in repair.
Crosslinking agents
Exogenous
Alkylating agents such as 1, 3-bis(2-chloroethyl)-1-nitrosourea (BCNU, carmustine)) and nitrogen mustard which are used in chemotherapy can cross link with DNA at N7 position of guanine on the opposite strands forming interstrand crosslink.
Cisplatin (cis-diamminedichloroplatinum(II)) and its derivatives forms DNA cross links as monoadduct, interstrand crosslink, intrastrand crosslink or DNA protein crosslink. Mostly it acts on the adjacent N-7 guanine forming 1, 2 intrastrand crosslink.
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