title: Nucleoids, a subnuclear system capable of chain elongation.
abstract: Nucleoids, prepared by salt extraction of non-DNase-digested nuclei, have properties similar, but not identical, to those of nuclear matrices which are prepared by salt extraction of DNase-digested nuclei. Nuclear matrices retained less pulse-labelled DNA, slightly less bound DNA polymerase alpha and DNA primase, but had greater in vitro DNA synthesis and in vitro priming. Nucleoids contained larger (110 S) DNA chains than nuclear matrices (30 S). Each type of residual nuclear structure could synthesize 4.5 S Okazaki fragments. When extracted with increasing concentrations of salt, DNase-digested nucleo lost the ability for further elongation of the 4.5 S DNA intermediate after 0.1-0.2 M NaCl, whereas undigested nuclei retained this ability up to 0.9 M NaCl. Chain elongation to 28 S DNA chains could be restored to nucleoids, but not to nuclear matrices, by the addition of nuclear extracts.
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond.
authors.forename: J M
authors.initials: JM
authors.lastname: Collins
authors.forename: S H
authors.initials: SH
authors.lastname: Wood
authors.forename: A K
authors.initials: AK
authors.lastname: Chu
mesh_terms: D000911:Antibodies, Monoclonal; D004247:DNA / Q000096:biosynthesis*; D011088:DNA Ligases / Q000378:metabolism; D004257:DNA Polymerase II / Q000378:metabolism; D019915:DNA Primase; D006367:HeLa Cells; D006801:Humans; D015530:Nuclear Matrix / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D012316:RNA Nucleotidyltransferases / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D011480:Protease Inhibitors; D004247:DNA; D019915:DNA Primase; D012316:RNA Nucleotidyltransferases; D004257:DNA Polymerase II; D011088:DNA Ligases