title: Architectural organization in E. coli nucleoid.
abstract: In contrast to organized hierarchical structure of eukaryotic chromosome, bacterial chromosomes are believed not to have such structures. The genomes of bacteria are condensed into a compact structure called the nucleoid. Among many architectural, histone-like proteins which associate with the chromosomal DNA is HU which is implicated in folding DNA into a compact structure by bending and wrapping DNA. Unlike the majority of other histone-like proteins, HU is highly conserved in eubacteria and unique in its ability to bind RNA. Furthermore, an HU mutation profoundly alters the cellular transcription profile and consequently has global effects on physiology and the lifestyle of E. coli. Here we provide a short overview of the mechanisms by which the nucleoid is organized into different topological domains. We propose that HU is a major player in creating domain-specific superhelicities and thus influences the transcription profile from the constituent promoters. This article is part of a Special Issue entitled: Chromatin in time and space.
authors.affiliation: Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Mirjana
authors.initials: M
authors.lastname: Macvanin
authors.forename: Sankar
authors.initials: S
authors.lastname: Adhya
mesh_terms: D002876:Chromosomes, Bacterial / Q000235:genetics* / Q000648:ultrastructure; D042003:DNA Packaging; D004269:DNA, Bacterial / Q000235:genetics / Q000648:ultrastructure; D004278:DNA, Superhelical / Q000235:genetics / Q000648:ultrastructure; D004268:DNA-Binding Proteins / Q000378:metabolism / Q000502:physiology; D004926:Escherichia coli / Q000235:genetics* / Q000648:ultrastructure; D029968:Escherichia coli Proteins / Q000378:metabolism / Q000502:physiology; D038101:Insulator Elements; D009690:Nucleic Acid Conformation; D012329:RNA, Bacterial / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D004278:DNA, Superhelical; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; C116822:hns protein, E coli