Summary: letter
nature genetics · advance online publication 1
Network motifs in the transcriptional regulation
network of Escherichia coli
Shai S. Shen-Orr1, Ron Milo2, Shmoolik Mangan1 & Uri Alon1,2
1Department of Molecular Cell Biology, 2Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel. Correspondence
should be addressed to U.A. (e-mail: urialon@wisemail.weizmann.ac.il).
Little is known about the design principles1­10 of transcrip-
tional regulation networks that control gene expression in
cells. Recent advances in data collection and analysis2,11,12,
however, are generating unprecedented amounts of informa-
tion about gene regulation networks. To understand these
complex wiring diagrams1­10,13, we sought to break down such
networks into basic building blocks2. We generalize the notion
of motifs, widely used for sequence analysis, to the level of
networks. We define `network motifs' as patterns of intercon-
nections that recur in many different parts of a network at fre-
quencies much higher than those found in randomized
networks. We applied new algorithms for systematically
detecting network motifs to one of the best-characterized reg-

Source: Alon, Uri - Departments of Molecular Cell Biology & Physics of Complex Systems, Weizmann Institute of Science

Collections: Biology and Medicine