title: A histone-like protein induces plasmid DNA to form liquid crystals in vitro and gene compaction in vivo.
abstract: The liquid crystalline state is a universal phenomenon involving the formation of an ordered structure via a self-assembly process that has attracted attention from numerous scientists. In this study, the dinoflagellate histone-like protein HCcp3 is shown to induce super-coiled pUC18 plasmid DNA to enter a liquid crystalline state in vitro, and the role of HCcp3 in gene condensation in vivo is also presented. The plasmid DNA (pDNA)-HCcp3 complex formed birefringent spherical particles with a semi-crystalline selected area electronic diffraction (SAED) pattern. Circular dichroism (CD) titrations of pDNA and HCcp3 were performed. Without HCcp3, pUC18 showed the characteristic B conformation. As the HCcp3 concentration increased, the 273 nm band sharply shifted to 282 nm. When the HCcp3 concentration became high, the base pair (bp)/dimer ratio fell below 42/1, and the CD spectra of the pDNA-HCcp3 complexes became similar to that of dehydrated A-form DNA. Microscopy results showed that HCcp3 compacted the super-coiled gene into a condensed state and that inclusion bodies were formed. Our results indicated that HCcp3 has significant roles in gene condensation both in vitro and in histone-less eukaryotes in vivo. The present study indicates that HCcp3 has great potential for applications in non-viral gene delivery systems, where HCcp3 may compact genetic material to form liquid crystals.
authors: Key Laboratory of Solid Waste Treatment and Resource Recycle & Fundamental Science on Nuclear Waste and Environmental Security Laboratory, Southwest University of Science and Technology, Mianyang 621010, Sichuan, China. shysun@swust.edu.cn.
authors: Shiyong
authors: S
authors: Sun
authors: Mingxue
authors: M
authors: Liu
authors: Faqin
authors: F
authors: Dong
authors: Shenglan
authors: S
authors: Fan
authors: Yanchen
authors: Y
authors: Yao
mesh_terms: D002942:Circular Dichroism; D004141:Dinoflagellida / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D018014:Gene Transfer Techniques; D006657:Histones / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050866:Liquid Crystals / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D010957:Plasmids / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics
chemical_list: D006657:Histones; D015800:Protozoan Proteins; D011994:Recombinant Proteins