Nucleosome spacing is compressed in active chromatin domains of chick erythroid cells.
We have cleaved the chromatin of embryonic and adult chicken erythroid cells using a novel nuclease that is capable of resolving clearly the nucleosomes of active chromatin. We found that in active chromatin, nucleosomes are spaced up to 40 base pairs closer together than in inactive chromatin. This was true for both "housekeeping" and "luxury" genes and was observed whether the digestion was carried out on isolated nuclei in vitro or by activating the endogenous nuclease in vivo. The close spacing extended several kilobases into flanking chromatin, indicating that this is a domain property of active chromatin, not just a characteristic of regions disrupted by transcription. A simple interpretation of our results is that the nucleosomes of active chromatin are mobile in vivo and, not being constrained by linker histones, freely move closer together.
Villeponteau
B
B
Department of Biological Chemistry, University of Michigan, Ann Arbor 48109-2007.
Brawley
J
J
Martinson
H G
HG
D000818:Animals; D002467:Cell Nucleus / Q000737:chemistry / Q000201:enzymology; D002642:Chick Embryo; D002843:Chromatin / Q000737:chemistry*; D004912:Erythrocytes / Q000737:chemistry* / Q000201:enzymology; D005914:Globins / Q000235:genetics; D006868:Hydrolysis; D009675:Novobiocin / Q000494:pharmacology; D009707:Nucleosomes / Q000737:chemistry*; D010047:Ovalbumin / Q000235:genetics; D010727:Phosphoric Diester Hydrolases / Q000737:chemistry; D011487:Protein Conformation
D002843:Chromatin; D009707:Nucleosomes; D009675:Novobiocin; D005914:Globins; D010047:Ovalbumin; D010727:Phosphoric Diester Hydrolases