dUDP + [thioredoxin]-disulfide + H2O <=> [thioredoxin]-dithiol + UDP
dudp + [thioredoxin]-disulfide + h2o <=> [thioredoxin]-dithiol + udp
dUDP + [thioredoxin]-disulfide + H2O <=> [thioredoxin]-dithiol + UDP
dudp + [thioredoxin]-disulfide + h2o <=> [thioredoxin]-dithiol + udp