MOTUS

• Documentation
• Software

What is Motus?

Motus is a tool for searching and inferring reaction motifs in metabolic networks.
A metabolic network is modelled as an undirected graph. Nodes (reactions) are labelled with EC numbers (code of 4 numbers expressing the chemistry of a reaction).
A reaction motif is defined as a set of (partial) EC numbers. An occurrence of the motif in the network is a set of nodes (reactions) which is connected and labelled by EC numbers that are similar to the ones of the motif.

You can use Motus in two ways:
SEARCH MODE: you know a motif and you want to know where and how many times it occurs in the network.
You need to specify a set of EC numbers
INFERENCE MODE: you want to know which motif appear repeatedly in the network.
You will need to specify the size of the motifs you want to infer and the degree of similarity you ask for an occurrence to be considered as such.

The data available on this website have been obtained from Biocyc and are downloadable in SBML format (DATA MODE).
Preprocessing of the data is also available as well as some statistics (STATISTICS MODE).

For more details :
V. Lacroix, C. G. Fernandes, and M.-F. Sagot. Motif search in graphs: Application to metabolic networks. Transactions in Computational Biology and Bioinformatics, vol. 3, pages 360-368, 2006.

An example

Example of Motif :

In this example, the occurrences of the motif are all linear but the colours are shuffled. MOTUS may also extract non-linear occurrences (ex: star-like topology). Indeed the specificity of the algorithm (compared to "network motif" extraction) is that there is no constraint on the topology of the occurrences, the nodes simply have to be connected.