Thioredoxin 2 from Escherichia coli is not involved in vivo in the recycling process of methionine sulfoxide reductase activities

► Trx2 from E. coli cannot substitute Trx 1 in vivo for recycling the Msr activities. ► The lack of growth of the metB1 trxA mutant on Met-O is due to low in vivo expression of Trx2. ► The catalytic efficiency of the fRMsr-recycling process with Trx 2 is low compared to that with Trx1.