RNAtemplates

RNAtemplates are RNA molecules that can serve as templates for the synthesis of a complementary nucleic acid strand by RNA-dependent polymerases or by reverse transcriptases. They are relevant in natural biology as well as in laboratory techniques, where RNA serves as the template guiding the creation of another nucleic acid.

In nature, RNA-templated processes are central to the life cycles of many RNA viruses, whose RNA genomes are copied by RNA-dependent RNA polymerases using the genomic RNA as a template to produce new RNA strands. In cellular systems, reverse transcriptases use RNA templates to generate complementary DNA, a mechanism exploited by retroviruses and retrotransposons. A well-known example of an RNA template within a complex enzyme is telomerase, whose RNA component provides the template for synthesis of telomeric DNA repeats at chromosome ends.

In laboratory settings, RNA templates are used in reverse transcription to produce complementary DNA (cDNA) for amplification and sequencing, as in RT-PCR and RT-qPCR. RNA can also be the substrate in RNA-templated transcription by certain RNA polymerases in vitro or in specialized assays that study polymerase fidelity and processivity. The efficiency and outcome of RNA-templated reactions depend on factors such as template length, secondary structure, and the properties of the polymerase.

See also RNA-dependent RNA polymerase, reverse transcription, telomerase, and RT-PCR.