title: DNA is wrapped by the nuclear aggregates of polyamines: the imaging evidence.
abstract: In the cell nucleus, putrescine, spermidine, and spermine self-assemble with phosphate ions to generate three forms of compounds, named nuclear aggregates of polyamines (NAPs), which may interact with DNA. In an in vitro setting mimicking the cell nucleus milieu, this molecular aggregation occurs within well-defined ratios. Structural and functional analogies exist between the in vitro NAPs (ivNAPs) and their extractive homologues. The present Article reports images of ivNAPs at different resolution levels. Independent of the DNA template, ivNAPs become hierarchically stacked to produce ultimately macroscopic filamentous structures. The ivNAP-DNA complexes arranged in long and repetitive structures that displayed the self-similar features of natural fractals when dehydrated onto glass slides. Atomic force microscopy showed that ivNAPs have a cyclic structure and dispose around the DNA in a tube-like arrangement. Overall, the images indicate that these aggregates envelope the genomic DNA, thus proving that NAPs play a crucial role in DNA compaction and functioning.
authors.affiliation: Istituto di Scienze dell'Alimentazione, CNR, via Roma 64, 83100 Avellino, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Iacomino
authors.forename: Gianluca
authors.initials: G
authors.lastname: Picariello
authors.forename: Francesca
authors.initials: F
authors.lastname: Sbrana
authors.forename: Aldo
authors.initials: A
authors.lastname: Di Luccia
authors.forename: Roberto
authors.initials: R
authors.lastname: Raiteri
authors.forename: Luciano
authors.initials: L
authors.lastname: D'Agostino
mesh_terms: D004247:DNA / Q000737:chemistry*; D006801:Humans; D006860:Hydrogen Bonding; D018625:Microscopy, Atomic Force; D008968:Molecular Conformation; D011073:Polyamines / Q000737:chemistry*
chemical_list: D011073:Polyamines; D004247:DNA