title: A novel nucleoid-associated protein specific to the actinobacteria.
abstract: Effective chromosome organization is central to the functioning of any cell. In bacteria, this organization is achieved through the concerted activity of multiple nucleoid-associated proteins. These proteins are not, however, universally conserved, and different groups of bacteria have distinct subsets that contribute to chromosome architecture. Here, we describe the characterization of a novel actinobacterial-specific protein in Streptomyces coelicolor. We show that sIHF (SCO1480) associates with the nucleoid and makes important contributions to chromosome condensation and chromosome segregation during Streptomyces sporulation. It also affects antibiotic production, suggesting an additional role in gene regulation. In vitro, sIHF binds DNA in a length-dependent but sequence-independent manner, without any obvious structural preferences. It does, however, impact the activity of topoisomerase, significantly altering DNA topology. The sIHF-DNA co-crystal structure reveals sIHF to be composed of two domains: a long N-terminal helix and a C-terminal helix-two turns-helix domain with two separate DNA interaction sites, suggesting a potential role in bridging DNA molecules.
authors: Department of Biology and Institute for Infectious Disease Research, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada.
authors: Julia P
authors: JP
authors: Swiercz
authors: Tamiza
authors: T
authors: Nanji
authors: Melanie
authors: M
authors: Gloyd
authors: Alba
authors: A
authors: Guarné
authors: Marie A
authors: MA
authors: Elliot
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020090:Chromosome Segregation; D026942:DNA Topoisomerases / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D009690:Nucleic Acid Conformation; D013171:Spores, Bacterial / Q000502:physiology; D048372:Streptomyces coelicolor / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D026942:DNA Topoisomerases