Kaycee A. Quarles

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One of the most exciting recent developments in RNA biology has been the discovery of small non-coding RNAs that affect gene expression through the RNA interference (RNAi) mechanism. Two major classes of RNAs involved in RNAi are small interfering RNA (siRNA) and microRNA (miRNA). Dicer, an RNase III enzyme, plays a central role in the RNAi pathway by(More)
The RNA world hypothesis proposes that nucleic acids were once responsible for both information storage and chemical catalysis, before the advent of coded protein synthesis. However, it is difficult to imagine how nucleic acid polymers first appeared, as the abiotic chemical formation of long nucleic acid polymers from mononucleotides or short(More)
MicroRNAs (miRNAs) affect gene regulation by base pairing with mRNA and contribute to the control of cellular homeostasis. The first step in miRNA maturation is conducted in the nucleus by the "microprocessor" complex made up of an RNase III enzyme, Drosha, that contains one dsRNA binding domain (dsRBD), and DGCR8, that contains two dsRBDs in tandem. The(More)
The prevalence of double-stranded RNA (dsRNA) in eukaryotic cells has only recently been appreciated. Of interest here, RNA silencing begins with dsRNA substrates that are bound by the dsRNA-binding domains (dsRBDs) of their processing proteins. Specifically, processing of microRNA (miRNA) in the nucleus minimally requires the enzyme Drosha and its(More)
Most noncoding RNAs function properly only when folded into complex three-dimensional (3D) structures, but the experimental determination of these structures remains challenging. Understanding of primary microRNA (miRNA) maturation is currently limited by a lack of determined structures for nonprocessed forms of the RNA. SHAPE chemistry efficiently(More)
BACKGROUND MicroRNAs (miRNAs) are critical post-transcriptional regulators of gene expression. Their precursors have a globally A-form helical geometry, which prevents most proteins from identifying their nucleotide sequence. This suggests the hypothesis that local structural features (e.g., bulges, internal loops) play a central role in specific(More)
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