Protein: ATP-dependent DNA helicase PIF1 (EC 3.6.4.12) (DNA repair and recombination helicase PIF1) (Petite integration frequency protein 1) (Telomere stability protein 1) (P07271)
Organism: Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
Function: DNA-dependent ATPase and 5'-3' DNA helicase required for the maintenance of both mitochondrial and nuclear genome stability. Efficiently unwinds G-quadruplex (G4) DNA structures and forked RNA-DNA hybrids. Appears to move along DNA in single nucleotide or base pair steps, powered by hydrolysis of 1 molecule of ATP. Processes at an unwinding rate of about 75 bp/s. Resolves G4 structures, preventing replication pausing and double-strand breaks (DSBs) at G4 motifs. Involved in the maintenance of telomeric DNA. Inhibits telomere elongation, de novo telomere formation and telomere addition to DSBs via catalytic inhibition of telomerase. Reduces the processivity of telomerase by displacing active telomerase from DNA ends. Releases telomerase by unwinding the short telomerase RNA/telomeric DNA hybrid that is the intermediate in the telomerase reaction. Involved in the maintenance of ribosomal (rDNA). Required for efficient fork arrest at the replication fork barrier within rDNA. Involved in the maintenance of mitochondrial (mtDNA). Required to maintain mtDNA under conditions that introduce dsDNA breaks in mtDNA, either preventing or repairing dsDNA breaks. May inhibit replication progression to allow time for repair. May have a general role in chromosomal replication by affecting Okazaki fragment maturation. May have a role in conjunction with DNA2 helicase/nuclease in 5'-flap extension during Okazaki fragment processing.
Subcellular location: [Isoform Nuclear]: Nucleus, nucleolus {ECO:0000269|PubMed:14562095, ECO:0000269|PubMed:16816432}. Note=Mainly concentrated in the nucleolus, and occasionally redistributes to single nuclear foci outside the nucleolus, probably sites of DNA repair. {ECO:0000269|PubMed:16816432}.; SUBCELLULAR LOCATION: [Isoform Mitochondrial]: Mitochondrion inner membrane {ECO:0000269|PubMed:14576278, ECO:0000269|PubMed:16816432, ECO:0000269|PubMed:1849081, ECO:0000269|PubMed:20655619}; Peripheral membrane protein {ECO:0000269|PubMed:20655619}; Matrix side {ECO:0000269|PubMed:20655619}. Note=Bound to the mitochondrial inner membrane either directly or indirectly via a protein complex. {ECO:0000269|PubMed:20655619}.
Interaction partners:
- ATP-dependent helicase SGS1
- DNA replication ATP-dependent helicase/nuclease DNA2
- Proliferating cell nuclear antigen
- DNA repair and recombination protein RAD52
- Cell division control protein 13
- DNA polymerase delta subunit 3
- ATP-dependent DNA helicase II subunit 1
- DNA repair protein RAD51
- Flap endonuclease 1
- ATP-dependent DNA helicase II subunit 2
Sequence:
MPKWIRSTLNHIIPRRPFICSFNSFLLLKNVSHAKLSFSMSSRGFRSNNFIQAQLKHPSILSKEDLDLLSDSDDWEEPDCIQLETEKQEKKIITDIHKEDPVDKKPMRDKNVMNFINKDSPLSWNDMFKPSIIQPPQLISENSFDQSSQKKSRSTGFKNPLRPALKKESSFDELQNNSISQERSLEMINENEKKKMQFGEKIAVLTQRPSFTELQNDQDDSNLNPHNGVKVKIPICLSKEQESIIKLAENGHNIFYTGSAGTGKSILLREMIKVLKGIYGRENVAVTASTGLAACNIGGITIHSFAGIGLGKGDADKLYKKVRRSRKHLRRWENIGALVVDEISMLDAELLDKLDFIARKIRKNHQPFGGIQLIFCGDFFQLPPVSKDPNRPTKFAFESKAWKEGVKMTIMLQKVFRQRGDVKFIDMLNRMRLGNIDDETEREFKKLSRPLPDDEIIPAELYSTRMEVERANNSRLSKLPGQVHIFNAIDGGALEDEELKERLLQNFLAPKELHLKVGAQVMMVKNLDATLVNGSLGKVIEFMDPETYFCYEALTNDPSMPPEKLETWAENPSKLKAAMEREQSDGEESAVASRKSSVKEGFAKSDIGEPVSPLDSSVFDFMKRVKTDDEVVLENIKRKEQLMQTIHQNSAGKRRLPLVRFKASDMSTRMVLVEPEDWAIEDENEKPLVSRVQLPLMLAWSLSIHKSQGQTLPKVKVDLRRVFEKGQAYVALSRAVSREGLQVLNFDRTRIKAHQKVIDFYLTLSSAESAYKQLEADEQVKKRKLDYAPGPKYKAKSKSKSNSPAPISATTQSNNGIAAMLQRHSRKRFQLKKESNSNQVHSLVSDEPRGQDTEDHILE