Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2011 Jan 25;39(10):4275–4283. doi: 10.1093/nar/gkr008

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© The Author(s) 2011. Published by Oxford University Press.

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.5), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

PMC Copyright notice

Figure 4. — Irreversible and reversible cruciform extrusion on the wtColE1 inverted repeat and its derivative mutColE1-5b. (A) The wtColE1 inverted repeat forms a perfect cruciform (B) in an irreversible fashion under conditions of negative supercoiling (n = −21). Immediately after the extrusion event, supercoiling is returned to n = −19 rotations to favor rewinding. Despite this no complete rewinding is observed, although unsuccessful attempts at refolding are regularly observed (down arrows). (C) The mutColE1-5b inverted repeat extrudes into an imperfect cruciform (D) in a reversible fashion, allowing for statistical analysis of the kinetics of cruciform extrusion and rewinding. The increased level of noise in the extension of the B-DNA state is due to the presence of A + T-rich regions flanking the inverted repeat (see Supplementary Figure S7).