When a helicase is not a helicase: dsDNA tracking by the motor protein EcoR124I

Louise K. Stanley; Ralf Seidel; Carsten Van Der Scheer; Nynke H. Dekker; Mark D. Szczelkun; Cees Dekker

doi:10.1038/sj.emboj.7601104

When a helicase is not a helicase: dsDNA tracking by the motor protein EcoR124I

Louise K. Stanley, Ralf Seidel, Carsten Van Der Scheer, Nynke H. Dekker, Mark D. Szczelkun (Lead / Corresponding author), Cees Dekker (Lead / Corresponding author)

Research output: Contribution to journal › Article › peer-review

56 Citations (Scopus)

Abstract

Using a combination of single molecule and bulk solution measurements, we have examined the DNA translocation activity of a helicase, the Type I restriction modification enzyme EcoR124I. We find that EcoR124I can translocate past covalent interstrand crosslinks, inconsistent with an obligatory unwinding mechanism. Instead, translocation of the intact dsDNA occurs principally via contacts to the sugar-phosphate backbone and bases of the 3′-5′ strand; contacts to the 5′-3′ strand are not essential for motion but do play a key role in stabilising the motor on the DNA. A model for dsDNA translocation is presented that could be applicable to a wide range of other enzyme complexes that are also labelled as helicases but which do not have actual unwinding activity.

Original language	English
Pages (from-to)	2230-2239
Number of pages	10
Journal	EMBO Journal
Volume	25
Issue number	10
Early online date	27 Apr 2006
DOIs	https://doi.org/10.1038/sj.emboj.7601104
Publication status	Published - 17 May 2006

Keywords

DNA translocation
Helicase
Motor protein
Restriction enzyme
Single molecule

ASJC Scopus subject areas

General Neuroscience
Molecular Biology
General Biochemistry,Genetics and Molecular Biology
General Immunology and Microbiology

Access to Document

10.1038/sj.emboj.7601104

Cite this

@article{840488982d064202b748643060a43f6a,

title = "When a helicase is not a helicase: dsDNA tracking by the motor protein EcoR124I",

abstract = "Using a combination of single molecule and bulk solution measurements, we have examined the DNA translocation activity of a helicase, the Type I restriction modification enzyme EcoR124I. We find that EcoR124I can translocate past covalent interstrand crosslinks, inconsistent with an obligatory unwinding mechanism. Instead, translocation of the intact dsDNA occurs principally via contacts to the sugar-phosphate backbone and bases of the 3′-5′ strand; contacts to the 5′-3′ strand are not essential for motion but do play a key role in stabilising the motor on the DNA. A model for dsDNA translocation is presented that could be applicable to a wide range of other enzyme complexes that are also labelled as helicases but which do not have actual unwinding activity.",

keywords = "DNA translocation, Helicase, Motor protein, Restriction enzyme, Single molecule",

author = "Stanley, {Louise K.} and Ralf Seidel and {Van Der Scheer}, Carsten and Dekker, {Nynke H.} and Szczelkun, {Mark D.} and Cees Dekker",

note = "Funding Information: The authors thank Dr Sean Colloms (University of Glasgow) for supplying the pJB43a plasmid and associated strains, and Prof. Malcolm White (University of St. Andrews) for supplying the Hje enzyme. This work was supported by grants from the Wellcome Trust (067439 and 071432). M.D.S. is a Wellcome Trust Senior Research Fellow in Basic Biomedical Sciences. L.K.S. is a Wellcome Trust Prize Ph.D. student. Funding to pay the Open Access publication charges for this article was provided by a Wellcome Trust {\textquoteleft}Value in People{\textquoteright} Grant to the University of Bristol, reference 078595. Publisher Copyright: & 2006 European Molecular Biology Organization. All Rights Reserved.",

year = "2006",

month = may,

day = "17",

doi = "10.1038/sj.emboj.7601104",

language = "English",

volume = "25",

pages = "2230--2239",

journal = "EMBO Journal",

issn = "0261-4189",

publisher = "EMBO Press",

number = "10",

}

TY - JOUR

T1 - When a helicase is not a helicase

T2 - dsDNA tracking by the motor protein EcoR124I

AU - Stanley, Louise K.

AU - Seidel, Ralf

AU - Van Der Scheer, Carsten

AU - Dekker, Nynke H.

AU - Szczelkun, Mark D.

AU - Dekker, Cees

N1 - Funding Information: The authors thank Dr Sean Colloms (University of Glasgow) for supplying the pJB43a plasmid and associated strains, and Prof. Malcolm White (University of St. Andrews) for supplying the Hje enzyme. This work was supported by grants from the Wellcome Trust (067439 and 071432). M.D.S. is a Wellcome Trust Senior Research Fellow in Basic Biomedical Sciences. L.K.S. is a Wellcome Trust Prize Ph.D. student. Funding to pay the Open Access publication charges for this article was provided by a Wellcome Trust ‘Value in People’ Grant to the University of Bristol, reference 078595. Publisher Copyright: & 2006 European Molecular Biology Organization. All Rights Reserved.

PY - 2006/5/17

Y1 - 2006/5/17

N2 - Using a combination of single molecule and bulk solution measurements, we have examined the DNA translocation activity of a helicase, the Type I restriction modification enzyme EcoR124I. We find that EcoR124I can translocate past covalent interstrand crosslinks, inconsistent with an obligatory unwinding mechanism. Instead, translocation of the intact dsDNA occurs principally via contacts to the sugar-phosphate backbone and bases of the 3′-5′ strand; contacts to the 5′-3′ strand are not essential for motion but do play a key role in stabilising the motor on the DNA. A model for dsDNA translocation is presented that could be applicable to a wide range of other enzyme complexes that are also labelled as helicases but which do not have actual unwinding activity.

AB - Using a combination of single molecule and bulk solution measurements, we have examined the DNA translocation activity of a helicase, the Type I restriction modification enzyme EcoR124I. We find that EcoR124I can translocate past covalent interstrand crosslinks, inconsistent with an obligatory unwinding mechanism. Instead, translocation of the intact dsDNA occurs principally via contacts to the sugar-phosphate backbone and bases of the 3′-5′ strand; contacts to the 5′-3′ strand are not essential for motion but do play a key role in stabilising the motor on the DNA. A model for dsDNA translocation is presented that could be applicable to a wide range of other enzyme complexes that are also labelled as helicases but which do not have actual unwinding activity.

KW - DNA translocation

KW - Helicase

KW - Motor protein

KW - Restriction enzyme

KW - Single molecule

UR - http://www.scopus.com/inward/record.url?scp=33646807817&partnerID=8YFLogxK

U2 - 10.1038/sj.emboj.7601104

DO - 10.1038/sj.emboj.7601104

M3 - Article

C2 - 16642041

AN - SCOPUS:33646807817

SN - 0261-4189

VL - 25

SP - 2230

EP - 2239

JO - EMBO Journal

JF - EMBO Journal

IS - 10

ER -

When a helicase is not a helicase: dsDNA tracking by the motor protein EcoR124I

Abstract

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this