Although DNA is most stable as a double-stranded helical structure, this must be unwound and the strands separated transiently for most DNA processing. The single-stranded intermediates are required for replication ( Machinery of DNA Replication), repair, recombination, and DNA transfer during conjugation, and, in each of these processes, duplex DNA unwinding is catalyzed by ubiquitous enzymes known as helicases. These proteins cause the destabilization of the hydrogen bonds between the complementary base pairs and the stacking of adjacent bases as it translocates along the DNA. This separation is coupled to hydrolysis of nucleoside triphosphate, most frequently ATP.
A number of enzymes have also been characterized that demonstrate RNA helicase activity (Bleichert and Baserga 2007; Jankowsky 2010). Structurally and functionally, RNA is a diverse molecule that is highly regulated. Helicases function in all aspects of RNA metabolism, such as...
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