ISSN:
1574-6968
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Abstract The tonB gene product is necessary for the energy-dependent transport of ferric chelates and vitamin B12 across the Escherichia coli outer membrane. When carried on multicopy plasmids, the cloned tonB gene complemented tonB hosts, restoring transport of ferri-siderophone complexes and vitamin B12, and susceptibility to the group B colicins and phage ф80. The levels of these activities were all markedly lower than when the tonB+ gene was present in single copy. This depression of TonB function occurred even when the chromosome carried the normal tonB+ allele, but plasmids carrying only a portion of the tonB gene, including the 5′-regulatory region, were not inhibitory.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1574-6968.1986.tb01282.x
Permalink