Stereochemistry of the conversions in vivo of L - and D -threonine into 2-oxobutanoic acid by the L - and D -threonine dehydratases of Serratia marcescens

The conversions of L-[3-2H]-(8) and D-[3-2H]-threonine (9) and of DL-(3S)-[3-2H]-2-aminobutanoic acid (10) into L-isoleucine (5) by mutant strains of Serratia marcescens were used to demonstrate that the conversions of L-(1) and D-threonine (7) into 2-oxobutanoic acid by the respective dehydratases take place with overall retention of configuration.