title: Chromosomal transformation in Bacillus subtilis is a non-polar recombination reaction.
abstract: Natural chromosomal transformation is one of the primary driving forces of bacterial evolution. This reaction involves the recombination of the internalized linear single-stranded (ss) DNA with the homologous resident duplex via RecA-mediated integration in concert with SsbA and DprA or RecO. We show that sequence divergence prevents Bacillus subtilis chromosomal transformation in a log-linear fashion, but it exerts a minor effect when the divergence is localized at a discrete end. In the nucleotide bound form, RecA shows no apparent preference to initiate recombination at the 3'- or 5'-complementary end of the linear duplex with circular ssDNA, but nucleotide hydrolysis is required when heterology is present at both ends. RecA·dATP initiates pairing of the linear 5' and 3' complementary ends, but only initiation at the 5'-end remains stably paired in the absence of SsbA. Our results suggest that during gene transfer RecA·ATP, in concert with SsbA and DprA or RecO, shows a moderate preference for the 3'-end of the duplex. We show that RecA-mediated recombination initiated at the 3'- or 5'-complementary end might have significant implication on the ecological diversification of bacterial species with natural transformation.
authors.affiliation: Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 28049 Madrid, Spain.
authors.forename: Begoña
authors.initials: B
authors.lastname: Carrasco
authors.affiliation: Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 28049 Madrid, Spain.
authors.forename: Ester
authors.initials: E
authors.lastname: Serrano
authors.affiliation: Department of Genetics, Cancer Genomics Netherlands, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Humberto
authors.identifier: http://orcid.org/0000-0003-2137-1233
authors.initials: H
authors.lastname: Sánchez
authors.affiliation: Department of Genetics, Cancer Genomics Netherlands, Erasmus University Medical Center, Rotterdam, The Netherlands Department of Radiation Oncology, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Claire
authors.initials: C
authors.lastname: Wyman
authors.affiliation: Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CNB-CSIC, 28049 Madrid, Spain jcalonso@cnb.csic.es.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Alonso
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002876:Chromosomes, Bacterial / Q000737:chemistry* / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics* / Q000378:metabolism; D004270:DNA, Circular / Q000235:genetics / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D011938:Rec A Recombinases / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004270:DNA, Circular; D004277:DNA, Single-Stranded; C093815:DprA protein, bacteria; D008565:Membrane Proteins; D011994:Recombinant Proteins; D011938:Rec A Recombinases