Figure 2.

Domain combination. (a) Domain architectures in a protein set can be represented as a network. A domain corresponds to a node, and edges refer to the co-occurrence or combination of a domain in the protein set under consideration. In a domain co-occurrence network, two domains are connected by an edge if they co-occurred in the same protein sequence. Here, we considered a domain combination network in which two domains must be located consecutively. Domain B is located between domains A and C, and so nodes A and C are not connected. (b) Combinations (A + B) and (B + A) are distinguished in this work.