chromosomal radial array or rosette

Introduction

There are 5 levels of folding of DNA in eukaryotic chromosomes. The radial array represents the 4th level of DNA folding. Nucleosomes (1st level of folding) are organized into solenoids (2nd level of folding). The solenoids in turn are folded into loops (3rd level of folding), which in turn form 6 loop rosette structures of 300 Kbp also known as radial arrays (4th level of folding). Topoisomerase 2 is found along DNA with a periodicity of 300 Kbp & is thought to be associated with formation of radial array structures. The radial arrays further fold into coils which form chromatid fibers (250 X 700 nm) which form the chromosomal banding seen on chromosomal staining.

More general terms

• DNA motif
• macromolecular complex

Component of

• chromosomal G-band