title: DNA Replication Initiation Is Blocked by a Distant Chromosome-Membrane Attachment.
abstract: Although it has been recognized for several decades that chromosome structure regulates the capacity of replication origins to initiate, very little is known about how or if cells actively regulate structure to direct initiation. We report that a localized inducible protein tether between the chromosome and cell membrane in E. coli cells imparts a rapid and complete block to replication initiation. Tethers, composed of a trans-membrane and transcription repressor fusion protein bound to an array of operator sequences, can be placed up to 1 Mb from the origin with no loss of penetrance. Tether-induced initiation blocking has no effect on elongation at pre-existing replication forks and does not cause cell or DNA damage. Whole-genome and site-specific fluorescent DNA labeling in tethered cells indicates that global nucleoid structure and chromosome organization are disrupted. Gene expression patterns, assayed by RNA sequencing, show that tethering induces global supercoiling changes, which are likely incompatible with replication initiation. Parallels between tether-induced initiation blocking and rifampicin treatment and the role of programmed changes in chromosome structure in replication control are discussed.
authors.affiliation: Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: David
authors.initials: D
authors.lastname: Magnan
authors.affiliation: Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Mohan C
authors.initials: MC
authors.lastname: Joshi
authors.affiliation: Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Barker
authors.affiliation: Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Bryan J
authors.initials: BJ
authors.lastname: Visser
authors.affiliation: Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA; Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA. Electronic address: bates@bcm.edu.
authors.forename: David
authors.initials: D
authors.lastname: Bates
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D002876:Chromosomes, Bacterial / Q000378:metabolism; D004261:DNA Replication; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018741:Replication Origin
chemical_list: D004269:DNA, Bacterial