T5 exonuclease is an enzyme that exhibits 5’→3′ exonuclease activity on double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA). It can initiate degradation from the 5′ ends or at gaps and nicks in linear or circular dsDNA, but it does not degrade supercoiled dsDNA. T5 exonuclease is commonly used in molecular biology applications for DNA manipulation and analysis.