The Lambda genome and virion. (A) Genome of phage lambda. Colored ORFs correspond to colored proteins in (B). Main transcripts are shown as arrows. (B) A model of phage lambda, indicating protein-protein interactions. Proteins in bold font have known structures (Table 1). Numbers indicate the number of protein copies in the particle. It is unclear whether M and L proteins are in the final particle or only required for assembly. (C) Electron micrograph of phage lambda. (A) and (C) modified after .