The protein interaction network of phage lambda. Interactions from this study have been integrated with previously published interactions ("literature"). Nodes in the network represent proteins and are colored according to their functional class (see color key). The protein-protein interactions are indicated by lines ("edges"). The edge color represents the source of the interactions, e.g., all red edges are previously reported interactions, all blue interactions were identified in our two-hybrid study, and all green interactions are previously known and are reproduced in our study.