Distinct Phage-Encoded Enzymes for Substitution of Deoxythymidine by Deoxyuridine in Phage Genomes.

ABSTRACT: DNA base modification is a common strategy used by bacteriophages to evade host immune detection. A prominent example is dU-DNA, where thymidine is globally replaced with 2'-deoxyuridine. Despite its widespread occurrence, dU-DNA's biosynthetic pathways and functional roles remain incompletely understood. Here, different enzymes supporting dU-DNA biosynthesis in phage PBS1, Roseophage DSS3_VP1, and Yersiniophage PhiR1-37 are identified and characterized. The dU nucleotide precursor is supplied by phage dCTP deaminases (Dcds). Thymidine nucleotides are degraded by dTMP phosphatases (Dtms) in PBS1 and DSS3_VP1, and by a dTTP pyrophosphatase (Dtt) in PhiR1-37, preventing incorporation into phage DNA. The dU-DNA, isolated from Yersiniophage PhiR1-37 or synthesized by PCR, demonstrates resistan

SUBMITTER: Li Y 

PROVIDER: S-EPMC12697855 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature