| 释义 |
nucleosome, n. Cytol.|ˈnjuːklɪəsəʊm|
[f. nucleo- + -some4: see also quot. 1975.]
Each of the bead-shaped particles occurring along the length of strands of DNA in eukaryotic chromosomes, consisting of a histone octamer surrounded by a coiled section of DNA.
1975P. Oudet et al. in Cell IV. 289/1 The fundamental structure of chromatin fibers is composed of a flexible chain of spherical particles with a diameter of 124–130 Å connected by DNA filaments. We have termed these particles ‘nucleosomes’, to evoke their nuclear origin and their resemblance to the ‘nu’ (ν) bodies described by Olins and Olins (1974). 1976Nature 12 Aug. 533/1 Electron micrographs of suitably lysed nuclei show linear arrays of interconnected roughly spherical particles about 10 nm diameter called beads, ν-bodies, or nucleosomes. 1985C. R. Leeson et al. Textbk. Histol. (ed. 5) i. 57/2 The nucleosome contains a double-stranded DNA fragment 140 to 200 base pairs long bound to an octameric histone core. 1990EMBO Jrnl. IX. 2911/1 The highly sensitive psoralen assay revealed that DNA replication appears to facilitate precise folding of DNA in the nucleosome.
Hence nucleoˈsomal a.
1976Proc. Nat. Acad. Sci. LXXIII. 2038/1, H2B, a nucleosomal histone, and H1, a nonnucleosomal histone, are both found throughout most chromosomal regions. 1988Biochem. XXVII. 5635/1 The forces that bind double-stranded DNA to the core-histone octamer to form nucleosomal particles appear to be essentially electrostatic. |