@article {310,
	title = {Molecular insights into RNA and DNA helicase evolution from the determinants of specificity for a DEAD-box RNA helicase.},
	journal = {Elife},
	volume = {4},
	year = {2014},
	month = {2014},
	abstract = {How different helicase families with a conserved catalytic {\textquoteleft}helicase core{\textquoteright} evolved to function on varied RNA and DNA substrates by diverse mechanisms remains unclear. In this study, we used Mss116, a yeast DEAD-box protein that utilizes ATP to locally unwind dsRNA, to investigate helicase specificity and mechanism. Our results define the molecular basis for the substrate specificity of a DEAD-box protein. Additionally, they show that Mss116 has ambiguous substrate-binding properties and interacts with all four NTPs and both RNA and DNA. The efficiency of unwinding correlates with the stability of the {\textquoteleft}closed-state{\textquoteright} helicase core, a complex with nucleotide and nucleic acid that forms as duplexes are unwound. Crystal structures reveal that core stability is modulated by family-specific interactions that favor certain substrates. This suggests how present-day helicases diversified from an ancestral core with broad specificity by retaining core closure as a common catalytic mechanism while optimizing substrate-binding interactions for different cellular functions.\&nbsp;},
	issn = {2050-084X},
	doi = {10.7554/eLife.04630},
	url = {http://elifesciences.org/content/3/e04630},
	author = {Mallam, Anna L and Sidote, David J and Lambowitz, Alan M}
}
