Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 23 June 2006:
Vol. 312. no. 5781, p. 1712
DOI: 10.1126/science.312.5781.1712h
Prev | Table of Contents | Next

This Week in Science

Double-stranded DNA viruses pump their genome into preassembled procapsids until the particles are filled to capacity with internal pressures higher than corked champagne. How is this internal "headful" density signaled to the outside packaging machinery? Insight comes from a 17 angstrom resolution asymmetric reconstruction of the infectious P22 virion by Lander et al. (p. 1791, published online 18 May). DNA is tightly spooled around the P22 portal, which is in a different conformation from the isolated portal. The authors suggest that DNA tightens around the portal as packaging density increases. When the headful density is reached, a conformational switch signals the termination of packaging.




To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)