A pair of DNA glucosyltransferases elevate counter-defense in bacteriophage T4 - PubMed
2 hours ago
- #Counter-defense
- #Bacteriophage T4
- #Glucosyltransferases
- Bacteriophage T4 encodes two glucosyltransferases (α-GT and β-GT) that modify DNA by adding glucose to hydroxymethylated deoxycytosines (5-hmC).
- β-GT has higher catalytic activity, while α-GT is expressed more strongly; during infection, α-GT glucosylates 66% of 5-hmC and β-GT glucosylates 33%.
- A single glucosyltransferase is enough to overcome Escherichia coli restriction-modification systems, but full protection requires at least 80% glucosylation.
- When facing hosts with DNA glycosylase Brig1 alongside type I and IV RM systems, T4 needs both glucosyltransferases to enable evasion and resist RM systems.
- Encoding multiple glucosyltransferases acts as a counter-defense mechanism against multiple antiphage defense systems simultaneously.