Interaction between HMG proteins (1 + 2) and the negative regulatory region 1 (NCR1) in the 5'-flanking sequence of the human beta-globin gene.

The pattern of high mobility group proteins 1 and 2 (HMG1,2) interaction with the 5'-flanking sequence of the human beta-globin gene has been analyzed by scanning tunnelling microscopy (STM). A 200 bp negative regulatory region in the 5'-flanking sequence of the human beta-globin gene can be folded by HMG proteins 1 and 2 into a circular structure (diameter 70 +/- 6 A) with a linear tail which seems to be a left-handed double helix structure.