title: [Structural organization of the bacterial nucleoid using endonucleolysis].
abstract: The fragmentation of bacterial deoxyribonucleoprotein (bDNP) in the spheroplasts of Escherichia coli, Serratia marcescens, Pseudomonas fluorescens and Micrococcus luteus by bacterial intracellular Ca2+ or Ca2+, Mg2+-dependent endonucleases in situ was studied. An electrophoresis of the extracted nuclease-split bDNP revealed the presence of high molecular weight (nuclease-resistant) and low molecular weight multiple fragments (100--120 nucleotide pairs). The electrophoretic mobility of the smallest nuclease-split DNA fragments in all bacterial species under study was similar, indicating the orderly structure of bDNP. Two total fractions whose electrophoretic mobility corresponded to that of the histones H2a and H2b from calf thymus were prevalent in the spectrum of acid-soluble bDNP proteins of gram-negative species. The heterogeneity of DNP with respect to its sensitivity to nucleases, is interaction with membranes and protein distribution pattern were revealed by treatment of the bacterial nucleoid with endogenous endonucleases, which probably reflects differences in the functional state of individual sites of the genome.
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002417:Cattle; D002876:Chromosomes, Bacterial / Q000648:ultrastructure*; D003851:Deoxyribonucleases / Q000378:metabolism*; D003852:Deoxyribonucleoproteins / Q000032:analysis*; D004720:Endonucleases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D006657:Histones / Q000032:analysis; D008274:Magnesium / Q000494:pharmacology; D008837:Micrococcus / Q000201:enzymology*; D009698:Nucleoproteins / Q000032:analysis*; D011551:Pseudomonas fluorescens / Q000201:enzymology*; D012706:Serratia marcescens / Q000201:enzymology*; D013104:Spheroplasts / Q000032:analysis; D013950:Thymus Gland / Q000032:analysis
chemical_list: D003852:Deoxyribonucleoproteins; D006657:Histones; D009698:Nucleoproteins; D003851:Deoxyribonucleases; D004720:Endonucleases; D008274:Magnesium; D002118:Calcium
vernacular_title: Issledovanie struktyrnoĭ organizatsii bakterial'nogo nukleoida pospedstvom endonukleoliza.