GRAMD1B and infection: This cluster includes many of the previously known E. coli genes whose absence prevents lambda infection, such as lamB. There is a strong correlation between the plaque assay and infection time course as eight (ΔdnaJ, ΔyneJ, ΔmalI, ΔmalT, ΔlamB, ΔmanZ, ΔrfaF, and ΔrfaC) of the nine strains that had zero plaques in all trials fell into this cluster (see Table S1).