BLM and RMI1 Alleviate RPA Inhibition of TopoIIIa Decatenase Activity

Jay Yang; Csanad Z Bachrati; Ian D Hickson; Grant W Brown

doi:10.1371/journal.pone.0041208

BLM and RMI1 Alleviate RPA Inhibition of TopoIIIa Decatenase Activity

Jay Yang, Csanad Z Bachrati, Ian D Hickson, Grant W Brown

5 Citations (Scopus)

Abstract

RPA is a single-stranded DNA binding protein that physically associates with the BLM complex. RPA stimulates BLM helicase activity as well as the double Holliday junction dissolution activity of the BLM-topoisomerase IIIα complex. We investigated the effect of RPA on the ssDNA decatenase activity of topoisomerase IIIα. We found that RPA and other ssDNA binding proteins inhibit decatenation by topoisomerase IIIα. Complex formation between BLM, TopoIIIα, and RMI1 ablates inhibition of decatenation by ssDNA binding proteins. Together, these data indicate that inhibition by RPA does not involve species-specific interactions between RPA and BLM-TopoIIIα-RMI1, which contrasts with RPA modulation of double Holliday junction dissolution. We propose that topoisomerase IIIα and RPA compete to bind to single-stranded regions of catenanes. Interactions with BLM and RMI1 enhance toposiomerase IIIα activity, promoting decatenation in the presence of RPA.

Original language	English
Journal	P L o S One
Volume	7
Issue number	7
Pages (from-to)	e41208
ISSN	1932-6203
DOIs	https://doi.org/10.1371/journal.pone.0041208
Publication status	Published - 20 Jul 2012

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title = "BLM and RMI1 Alleviate RPA Inhibition of TopoIIIa Decatenase Activity",

abstract = "RPA is a single-stranded DNA binding protein that physically associates with the BLM complex. RPA stimulates BLM helicase activity as well as the double Holliday junction dissolution activity of the BLM-topoisomerase IIIα complex. We investigated the effect of RPA on the ssDNA decatenase activity of topoisomerase IIIα. We found that RPA and other ssDNA binding proteins inhibit decatenation by topoisomerase IIIα. Complex formation between BLM, TopoIIIα, and RMI1 ablates inhibition of decatenation by ssDNA binding proteins. Together, these data indicate that inhibition by RPA does not involve species-specific interactions between RPA and BLM-TopoIIIα-RMI1, which contrasts with RPA modulation of double Holliday junction dissolution. We propose that topoisomerase IIIα and RPA compete to bind to single-stranded regions of catenanes. Interactions with BLM and RMI1 enhance toposiomerase IIIα activity, promoting decatenation in the presence of RPA.",

author = "Jay Yang and Bachrati, {Csanad Z} and Hickson, {Ian D} and Brown, {Grant W}",

year = "2012",

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language = "English",

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TY - JOUR

T1 - BLM and RMI1 Alleviate RPA Inhibition of TopoIIIa Decatenase Activity

AU - Yang, Jay

AU - Bachrati, Csanad Z

AU - Hickson, Ian D

AU - Brown, Grant W

PY - 2012/7/20

Y1 - 2012/7/20

N2 - RPA is a single-stranded DNA binding protein that physically associates with the BLM complex. RPA stimulates BLM helicase activity as well as the double Holliday junction dissolution activity of the BLM-topoisomerase IIIα complex. We investigated the effect of RPA on the ssDNA decatenase activity of topoisomerase IIIα. We found that RPA and other ssDNA binding proteins inhibit decatenation by topoisomerase IIIα. Complex formation between BLM, TopoIIIα, and RMI1 ablates inhibition of decatenation by ssDNA binding proteins. Together, these data indicate that inhibition by RPA does not involve species-specific interactions between RPA and BLM-TopoIIIα-RMI1, which contrasts with RPA modulation of double Holliday junction dissolution. We propose that topoisomerase IIIα and RPA compete to bind to single-stranded regions of catenanes. Interactions with BLM and RMI1 enhance toposiomerase IIIα activity, promoting decatenation in the presence of RPA.

AB - RPA is a single-stranded DNA binding protein that physically associates with the BLM complex. RPA stimulates BLM helicase activity as well as the double Holliday junction dissolution activity of the BLM-topoisomerase IIIα complex. We investigated the effect of RPA on the ssDNA decatenase activity of topoisomerase IIIα. We found that RPA and other ssDNA binding proteins inhibit decatenation by topoisomerase IIIα. Complex formation between BLM, TopoIIIα, and RMI1 ablates inhibition of decatenation by ssDNA binding proteins. Together, these data indicate that inhibition by RPA does not involve species-specific interactions between RPA and BLM-TopoIIIα-RMI1, which contrasts with RPA modulation of double Holliday junction dissolution. We propose that topoisomerase IIIα and RPA compete to bind to single-stranded regions of catenanes. Interactions with BLM and RMI1 enhance toposiomerase IIIα activity, promoting decatenation in the presence of RPA.

U2 - 10.1371/journal.pone.0041208

DO - 10.1371/journal.pone.0041208

M3 - Journal article

C2 - 22911760

SN - 1932-6203

VL - 7

SP - e41208

JO - PLoS Computational Biology

JF - PLoS Computational Biology

IS - 7

ER -

BLM and RMI1 Alleviate RPA Inhibition of TopoIIIa Decatenase Activity

Abstract

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