Literature summary for 5.6.2.3 extracted from

Nickens, D.G.; Rogers, C.M.; Bochman, M.L.
The Saccharomyces cerevisiae Hrq1 and Pif1 DNA helicases synergistically modulate telomerase activity in vitro (2018), J. Biol. Chem., 293, 14481-14496 .

Search for more literature for 5.6.2.3

Activating Compound

Activating Compound	Comment	Organism	Structure
RNA-DNA hybrid	Pif1 helicase activity is stimulated by RNA-DNA hybrids	Saccharomyces cerevisiae

Protein Variants

Protein Variants	Comment	Organism
K264A	site-directed mutagenesis, catalytically inactive mutant, the mutant shows increased KD value, but unaltered DNA binding compared to wild-type. Pif1-K264A has no significant effects on overall telomerase activity relative to the telomerase alone control	Saccharomyces cerevisiae

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Mg2+	required	Saccharomyces cerevisiae

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
ATP + H2O	Saccharomyces cerevisiae	-	ADP + phosphate	-	?
ATP + H2O	Saccharomyces cerevisiae ATCC 204508	-	ADP + phosphate	-	?

Organism

Organism	UniProt	Comment	Textmining
Saccharomyces cerevisiae	P07271	-	-
Saccharomyces cerevisiae ATCC 204508	P07271	-	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
ATP + H2O	-	Saccharomyces cerevisiae	ADP + phosphate	-	?
ATP + H2O	-	Saccharomyces cerevisiae ATCC 204508	ADP + phosphate	-	?
additional information	Saccharomyces cerevisiae Hrq1 and Pif1 DNA helicases synergistically modulate telomerase activity in vitro. The helicases alone have equal-but-opposite biphasic effects on telomerase, with Hrq1 stimulating activity at high concentrations. When the helicases are combined in reactions, they synergistically inhibit or stimulate telomerase activity depending on which helicase is catalytically active. Hrq1 affects telomerase activity by a different mechanism than Pif1. Pif1 helicase activity is stimulated by RNA-DNA hybrids	Saccharomyces cerevisiae	?	-	-
additional information	Saccharomyces cerevisiae Hrq1 and Pif1 DNA helicases synergistically modulate telomerase activity in vitro. The helicases alone have equal-but-opposite biphasic effects on telomerase, with Hrq1 stimulating activity at high concentrations. When the helicases are combined in reactions, they synergistically inhibit or stimulate telomerase activity depending on which helicase is catalytically active. Hrq1 affects telomerase activity by a different mechanism than Pif1. Pif1 helicase activity is stimulated by RNA-DNA hybrids	Saccharomyces cerevisiae ATCC 204508	?	-	-

Synonyms

Synonyms	Comment	Organism
PIF1	-	Saccharomyces cerevisiae
PIF1 helicase	-	Saccharomyces cerevisiae

General Information

General Information	Comment	Organism
metabolism	Saccharomyces cerevisiae Hrq1 and Pif1 DNA helicases synergistically modulate telomerase activity in vitro. The helicases alone have equal-but-opposite biphasic effects on telomerase, with Hrq1 stimulating activity at high concentrations. When the helicases are combined in reactions, they synergistically inhibit or stimulate telomerase activity depending on which helicase is catalytically active. Hrq1 and Pif1 interact and their concerted activities ensure proper telomere length homeostasis in vivo. Modelling of Hrq1 and Pif1 cooperatively contributing to telomere length homeostasis in yeast, overview. Hrq1 affects telomerase activity by a different mechanism than Pif1. Pif1 acts on a long (50 nt) primer. Pif1 shows a complex activity profile over the range of concentrations tested	Saccharomyces cerevisiae
physiological function	Saccharomyces cerevisiae Pif1 DNA helicase synergistically modulates telomerase activity. It is a catalytic inhibitor of telomerase. The enzyme is involved in telomerase regulation together with DNA helicase Hrq1	Saccharomyces cerevisiae

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Release 2023.1 (January 2023)