title: Biochemical studies of the Saccharomyces cerevisiae Mph1 helicase on junction-containing DNA structures.
abstract: Saccharomyces cerevisiae Mph1 is a 3-5' DNA helicase, required for the maintenance of genome integrity. In order to understand the ATPase/helicase role of Mph1 in genome stability, we characterized its helicase activity with a variety of DNA substrates, focusing on its action on junction structures containing three or four DNA strands. Consistent with its 3' to 5' directionality, Mph1 displaced 3'-flap substrates in double-fixed or equilibrating flap substrates. Surprisingly, Mph1 displaced the 5'-flap strand more efficiently than the 3' flap strand from double-flap substrates, which is not expected for a 3-5' DNA helicase. For this to occur, Mph1 required a threshold size (>5 nt) of 5' single-stranded DNA flap. Based on the unique substrate requirements of Mph1 defined in this study, we propose that the helicase/ATPase activity of Mph1 play roles in converting multiple-stranded DNA structures into structures cleavable by processing enzymes such as Fen1. We also found that the helicase activity of Mph1 was used to cause structural alterations required for restoration of replication forks stalled due to damaged template. The helicase properties of Mph1 reported here could explain how it resolves D-loop structure, and are in keeping with a model proposed for the error-free damage avoidance pathway.
authors.affiliation: Department of Biological Sciences, Center for DNA Replication and Genome Instability, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Korea.
authors.forename: Young-Hoon
authors.initials: YH
authors.lastname: Kang
authors.forename: Palinda Ruvan
authors.initials: PR
authors.lastname: Munashingha
authors.forename: Chul-Hwan
authors.initials: CH
authors.lastname: Lee
authors.forename: Tuan Anh
authors.initials: TA
authors.lastname: Nguyen
authors.forename: Yeon-Soo
authors.initials: YS
authors.lastname: Seo
mesh_terms: D053487:DEAD-box RNA Helicases / Q000378:metabolism*; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D004261:DNA Replication; D004277:DNA, Single-Stranded / Q000378:metabolism; D009690:Nucleic Acid Conformation; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
chemical_list: D004277:DNA, Single-Stranded; D029701:Saccharomyces cerevisiae Proteins; D004247:DNA; C491240:MPH1 protein, S cerevisiae; D053487:DEAD-box RNA Helicases
references.citation: EMBO Rep. 2000 Jul;1(1):80-4
references.pmid: 11256630
references.citation: Proc Natl Acad Sci U S A. 2001 Jan 2;98(1):54-9
references.pmid: 11136247
references.citation: Crit Rev Biochem Mol Biol. 2010 Apr;45(2):71-96
references.pmid: 20131965
references.citation: Genetics. 2004 Apr;166(4):1673-86
references.pmid: 15126389
references.citation: J Biol Chem. 2009 Apr 17;284(16):10376-86
references.pmid: 19181670
references.citation: Mol Cell. 2007 Oct 12;28(1):167-75
references.pmid: 17936713
references.citation: Nucleic Acids Res. 2002 Oct 15;30(20):4534-47
references.pmid: 12384601
references.citation: Annu Rev Biochem. 1990;59:289-329
references.pmid: 2165383
references.citation: Genes Dev. 1992 Nov;6(11):2214-20
references.pmid: 1427081
references.citation: Proc Natl Acad Sci U S A. 2008 Oct 21;105(42):16107-12
references.pmid: 18843105
references.citation: Nucleic Acids Res. 1996 Jun 1;24(11):1992-8
references.pmid: 8668527
references.citation: Proc Natl Acad Sci U S A. 2000 Jun 6;97(12):6504-8
references.pmid: 10823897
references.citation: Cell. 1995 May 19;81(4):533-40
references.pmid: 7758107
references.citation: DNA Repair (Amst). 2010 Mar 2;9(3):224-36
references.pmid: 20117061
references.citation: Yeast. 2010 Jan;27(1):11-27
references.pmid: 19918932
references.citation: Genes Dev. 2007 Dec 1;21(23):3085-94
references.pmid: 18003860
references.citation: Mol Cell. 2008 Oct 10;32(1):118-28
references.pmid: 18851838
references.citation: Nucleic Acids Res. 2004 Aug 09;32(14):4205-16
references.pmid: 15302919
references.citation: DNA Repair (Amst). 2011 Jan 2;10(1):45-55
references.pmid: 20951099
references.citation: J Biol Chem. 2004 Apr 30;279(18):18099-102
references.pmid: 15023996
references.citation: Nat Genet. 2005 Sep;37(9):958-63
references.pmid: 16116422
references.citation: J Biol Chem. 2002 Jun 28;277(26):23236-45
references.pmid: 11956187
references.citation: J Biol Chem. 2008 Jul 18;283(29):20231-42
references.pmid: 18495662
references.citation: Proc Natl Acad Sci U S A. 2009 Dec 15;106(50):21252-7
references.pmid: 19995966
references.citation: Mol Gen Genet. 1999 Dec;262(4-5):683-702
references.pmid: 10628851
references.citation: J Biol Chem. 2005 Mar 4;280(9):7854-60
references.pmid: 15634678
references.citation: Genes Dev. 2004 Aug 1;18(15):1886-97
references.pmid: 15289460
references.citation: J Mol Biol. 1985 Sep 20;185(2):431-43
references.pmid: 2997450
references.citation: EMBO J. 2003 Nov 17;22(22):6148-60
references.pmid: 14609960
references.citation: Methods Mol Biol. 2009;521:361-79
references.pmid: 19563117
references.citation: Annu Rev Biophys. 2008;37:317-36
references.pmid: 18573084
references.citation: Genetics. 2000 Jul;155(3):1069-81
references.pmid: 10880470
references.citation: Proc Natl Acad Sci U S A. 1990 Aug;87(16):6383-7
references.pmid: 2166955
references.citation: J Biol Chem. 2009 Dec 11;284(50):34682-91
references.pmid: 19812417
references.citation: Nature. 2006 Aug 3;442(7102):590-3
references.pmid: 16862129
references.citation: Nucleic Acids Res. 2006 Apr 04;34(6):1854-64
references.pmid: 16595799
references.citation: Eukaryot Cell. 2010 Feb;9(2):315-24
references.pmid: 20008080
references.citation: Mol Cell Biol. 2004 May;24(9):4049-64
references.pmid: 15082797
references.citation: J Bacteriol. 2008 Apr;190(8):3006-17
references.pmid: 18296528
references.citation: J Biol Chem. 2008 Sep 5;283(36):24698-706
references.pmid: 18617519
references.citation: Nucleic Acids Res. 1995 Nov 11;23(21):4303-11
references.pmid: 7501450
references.citation: Mol Cell. 2008 Jan 18;29(1):141-8
references.pmid: 18206976
references.citation: Genes Dev. 2009 Jan 1;23(1):67-79
references.pmid: 19136626