Related Experiment Video
Updated: Mar 27, 2026

Sequence-specific and Selective Recognition of Double-stranded RNAs over Single-stranded RNAs by Chemically Modified Peptide Nucleic Acids
Published on: September 21, 2017
Yeast Helicase Pif1 Unwinds RNA:DNA Hybrids with Higher Processivity than DNA:DNA Duplexes
Shubeena Chib1, Alicia K Byrd1, Kevin D Raney1
1From the Department of Biochemistry and Molecular Biology University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205.
Abstract:
Saccharomyces cerevisiae Pif1, an SF1B helicase, has been implicated in both mitochondrial and nuclear functions. Here we have characterized the preference of Pif1 for RNA:DNA heteroduplexes in vitro by investigating several kinetic parameters associated with unwinding. We show that the preferential unwinding of RNA:DNA hybrids is due to neither specific binding nor differences in the rate of strand separation. Instead, Pif1 is capable of unwinding RNA:DNA heteroduplexes with moderately greater processivity compared with its duplex DNA:DNA counterparts. This higher processivity of Pif1 is attributed to slower dissociation from RNA:DNA hybrids. Biologically, this preferential role of the helicase may contribute to its functions at both telomeric and nontelomeric sites.
Related Concept Videos
Restarting Stalled Replication Forks
Homologous Recombination
DNA Helicases
Single-Strand DNA Binding Proteins
DNA Topoisomerases
Types and Mechanism of action
Topoisomerases are divided into two main types. ...
The DNA Replication Fork

