DNA topology of the ordered chromatin domain 5' to the human c-myc gene.
DNA restriction fragments located 5' to the human c-myc gene display anomalous electrophoretic mobility on polyacrylamide gels. Computer modeling of the c-myc flanking DNA suggests that the slow-moving DNA fragments spanning nucleotides -1690 to -1054 (relative to c-myc promoter P1) and -718 to -452 form large left handed superhelices or curved structures while the fast-moving DNA fragment spanning nucleotides -407 to +78 has an unusually straight structure. These analyses also predict a periodic array of localized regions of bending through the superhelical domains. Micrococcal nuclease digestion of isolated nuclei reveals that the slow-moving DNA fragments exist in an ordered chromatin structure stable to nuclease, whereas the digestion pattern of the fast-moving DNA fragment suggests a less ordered array of nucleosomes or a non-nucleosomal chromatin structure.
Kumar
S
S
Department of Biochemistry, Wright State University, Dayton, OH 45435.
Leffak
M
M
D001483:Base Sequence; D002843:Chromatin / Q000032:analysis*; D004278:DNA, Superhelical / Q000302:isolation & purification; D006367:HeLa Cells; D006801:Humans; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D011519:Proto-Oncogenes; D015183:Restriction Mapping; D012984:Software
D002843:Chromatin; D004278:DNA, Superhelical