title: Structural studies on Allium cepa L. chromatin: enhanced stability of internucleosome interactions in plant chromatin.
abstract: The pattern of micrococcal nuclease digestion of chromatin from different organs of Allium cepa has been studied. The DNA from small oligonucleosomes appears to be highly degraded and heterogeneous. In solutions of intermediate ionic strength (0.15 M NaCl) histones H2A and H2B form dimers, however at high salt concentrations (2 M NaCl) they tend to form complexes of higher order, such as tetramers. It is proposed that a correlation exists between the ability of these proteins to form tetramers and the particular stability of internucleosome interactions.
mesh_terms: D002499:Centrifugation, Density Gradient; D002843:Chromatin / Q000032:analysis*; D004587:Electrophoresis, Agar Gel; D006657:Histones / Q000032:analysis; D008836:Micrococcal Nuclease / Q000378:metabolism; D009707:Nucleosomes / Q000032:analysis; D010944:Plants / Q000235:genetics*; D014018:Tissue Distribution
chemical_list: D002843:Chromatin; D006657:Histones; D009707:Nucleosomes; D008836:Micrococcal Nuclease