Experimental test of connector rotation during DNA packaging into bacteriophage phi29 capsids.

ABSTRACT: The bacteriophage phi29 generates large forces to compact its double-stranded DNA genome into a protein capsid by means of a portal motor complex. Several mechanical models for the generation of these high forces by the motor complex predict coupling of DNA translocation to rotation of the head-tail connector dodecamer. Putative connector rotation is investigated here by combining the methods of single-molecule force spectroscopy with polarization-sensitive single-molecule fluorescence. In our experiment, we observe motor function in several packaging complexes in parallel using video microscopy of bead position in a magnetic trap. At the same time, we follow the orientation of single fluorophores attached to the portal motor connector. From our data, we can exclude connector rotation with

SUBMITTER: Hugel T 

PROVIDER: S-EPMC1800307 | biostudies-literature | 2007 Mar

REPOSITORIES: biostudies-literature