RT Journal Article
T1 DNA synthesis determines the binding mode of the human mitochondrial single-stranded DNA-binding protein
A1 Morin, José A.
A1 Cerrón Campoo, Fernando
A1 Jarillo Díaz, Javier
A1 Beltrán De Heredia Rodríguez, Elena
A1 Ciesielski, Grzegorz L.
A1 Arias González, J. Ricardo
A1 Kaguni, Laurie S.
A1 Cao García, Francisco Javier
A1 Ibarra, Borja
AB Single-stranded DNA-binding proteins (SSBs) play a key role in genome maintenance, binding and organizing single-stranded DNA (ssDNA) intermediates. Multimeric SSBs, such as the human mitochondrial SSB (HmtSSB), presentmultiple sites to interact with ssDNA, which has been shown in vitro to enable them to bind a variable number of single-stranded nucleotides depending on the salt and protein concentration. It has long been suggested that different binding modes might be used selectively for different functions. To study this possibility, we used optical tweezers to determine and compare the structure and energetics of long, individual HmtSSB-DNA complexes assembled on preformed ssDNA and on ssDNA generated gradually during 'in situ' DNA synthesis. We show that HmtSSB binds to preformed ssDNA in two major modes, depending on salt and protein concentration. However, when protein binding was coupled to strand-displacement DNA synthesis, only one of the two binding modes was observed under all experimental conditions. Our results reveal a key role for the gradual generation of ssDNA in modulating the binding mode of a multimeric SSB protein and consequently, in generating the appropriate nucleoprotein structure for DNA synthetic reactions required for genome maintenance.
PB Oxford University Press
SN 0305-1048
YR 2017
FD 2017-07-07
LK https://hdl.handle.net/20.500.14352/18113
UL https://hdl.handle.net/20.500.14352/18113
LA eng
NO © Oxford University Press 2017.Spanish Ministry of Economy and Competitiveness [MAT2015-71806-R to J.R.A-G, FIS2010-17440, FIS2015-67765-R to F.J.C., BFU2012-31825, BFU2015-63714-R to B.I.]; Spanish Ministry of Education, Culture and Sport [FPU13/02934 to J.J., FPU13/02826 to E.B-H.]; National Institutes of Health [GM45925 to L.S.K.]; University of Tampere (to G.L.C.); Programa de Financiacion Universidad Complutense de Madrid-Santander Universidades [CT45/15-CT46/15 to F.C.]. Funding for open access charge: Spanish Ministry of Economy and Competitiveness [BFU2015-63714-R].
NO Ministerio de Economía y Competitividad (MINECO)
NO Ministerio de Educación, Cultura y Deporte (MECD)
NO National Institutes of Health
NO University of Tampere
NO Universidad Complutense de Madrid/Banco de Santander
DS Docta Complutense
RD 10 abr 2025