title: Structure of Herpesvirus saimiri genomes: arrangement of heavy and light sequences in the M genome.
abstract: Herpesvirus saimiri contains two species of DNA molecules. (i) The M genome is composed of 70% light (L) DNA (36% cytosine plus guanine; density in CsCl, 1.695 g/ml), which consists of unique sequences, and 30% heavy (H) DNA (71% cytosine plus guanine; density, 1.729 g/ml). (ii) The H genome contains heavy sequences exclusively. H sequences in M and H genomes cross-hybridize completely and are cleaved identically by restriction endonuclease R-Sma I into four classes of fragments with molecular weights of about 360,000, 300,000, 130,000 and 40,000, respectively. H sequences are chains of identical repeat units in tandem arrangement. The molecular weight of each repeat unit is about 830,000. L sequences have no cleavage site for endo R-Sma I H sequences are terminally arranged at both ends of the M genome, as seen by electron microscopy after partial denaturation. The length of the individual heavy ends varies between 21 mum and less than 1 mum, whereas the light region is uniform in size (35.3+/-0.35 mum). As a rule, molecules with a long heavy end at one side have a short heavy end at the other side, thus giving rise to a limited size heterogeneity. Orientation of M DNA molecules by the denaturation map of the light region shows that the longer heavy end may be located at the left or at the right side of the M genome.
mesh_terms: D001483:Base Sequence; D003596:Cytosine / Q000032:analysis; D004262:DNA Restriction Enzymes / Q000378:metabolism; D004279:DNA, Viral / Q000032:analysis*; D006147:Guanine / Q000032:analysis; D006564:Herpesviridae / Q000032:analysis*; D006567:Herpesvirus 2, Saimiriine / Q000032:analysis*; D009691:Nucleic Acid Denaturation; D012706:Serratia marcescens / Q000201:enzymology
chemical_list: D004279:DNA, Viral; D006147:Guanine; D003596:Cytosine; D004262:DNA Restriction Enzymes