Networking E. coli

The paper: G. Butland et al., "Interaction network containing conserved and essential protein complexes in Escherichia coli,' Nature, 433:531-7, 2005. (Cited in 91 papers) The finding: Jack Greenblatt and Andrew Emili from the University of Toronto led a team of Canadian researchers that produced a large-scale map of a bacterial interaction network by tagging and purifying protein complexes from 23% of the Escherichia coli genome.

David Secko
Feb 28, 2007

The paper:

G. Butland et al., "Interaction network containing conserved and essential protein complexes in Escherichia coli,' Nature, 433:531-7, 2005. (Cited in 91 papers)

The finding:

Jack Greenblatt and Andrew Emili from the University of Toronto led a team of Canadian researchers that produced a large-scale map of a bacterial interaction network by tagging and purifying protein complexes from 23% of the Escherichia coli genome.

The wrinkle:

Greenblatt's and Emili's group was one of the first to move away from studying binary protein interactions in prokaryotes to examining multiprotein complexes on a genome scale, says Russell Finley Jr., from Wayne State University. "Not only that, they importantly did validation analysis on the complexes to show that the information will be useful to biologists," says Finley, who studies protein interaction networks in Drosophila.

The challenge:

While Greenblatt's and Emili's group has gone on to do similar work in yeast, a hurdle still remains: how to apply their technique to other bacteria. "E. coli is an important organism, but it's one of a thousand interesting prokaryotes," says Finley, "and it's hard to do this type of thing in other prokaryotes due to protein expression difficulties."

The next step:

The initial study left approximately 75% of the genome untouched, and that gap is being worked on now, says Greenblatt. "We're halfway finished," he adds. The next step will then be all those proteins that don't interact.

Numbers from the paper:
1,000 - E. coli open-reading frames targeted
857 - proteins successfully tagged
648 - tagged proteins purified
5,254 - protein-protein interactions identified