ATP8B1 and nutritional disorder: It converts nucleotides into deoxynucleotides (Fig. 21B).190 Phage-encoded RNRs are important for rapid phage DNA synthesis191 and effective reproduction.192 ICP1 phage encodes a class Ia RNR and a class III RNR on its genome,193 both of which require iron as a cofactor.190 It has been shown that intracellular iron deficiency caused by an iron chelator can attenuate RNR activity in human cells.194 Therefore, it is possible that enterobactin and linear enterobactin sequester iron away from ICP1-infected V. cholerae, which inhibits ICP1-encoded RNR activity and impedes rapid ICP1 proliferation.