1. Nucleoproteins are complexes formed by proteins conjugated with nucleic acids (either DNA or RNA). However It could sometimes mean just a protein relevant to nucleic acid. Typical nucleoproteins include ribosomes, nucleosomes and viral nucleocapsid(caspid + viral genome). == Structures == Nucleoproteins tend to be positively charged. The fact facilitates their interaction with the negatively charged nucleic acid chains. The tertiary structures and biological functions of many nucleoproteins are understood. Important techniques for finding the structures of nucleoproteins include X-ray diffraction, nuclear magnetic resonance and cryo-electron microscopy. === Viruses === Virus genomes (either DNA or RNA) are extremely tightly packed into the viral capsid. Many viruses are therefore little more than an organised collection of nucleoproteins with their binding sites pointing inwards. Structurally characterised viral nucleoproteins include influenza, rabies, Ebola, Bunyamwera, Schmallenberg,... from wikipedia.org