Triple helix basic types

Fig. 12.4. Triple helix formation. Two basic types and a combination of these can be distinguished (I). Triple helices may occur naturally in a duplex (II) (Wells et al., 1988). One of the applications of triple helices is the protection of a particular site against a restriction enzyme (III). Mismatches are allowed to a certain degree (IV rounded to 0.5°C data from Mergny et al., 1991).

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