Table 2.

Enantioselectivity of selected SMFMO mutants towards the substrates methyl-p-tolyl sulfide and ethyl phenyl sulphide.

Variant	Absolute configuration and enantiomeric excess of sulfoxide product
	Methyl-p-tolyl sulfoxide product of biotransformation of methyl-p-tolyl sulfide	Ethyl phenyl sulfoxide product of biotransformation of ethyl phenyl sulfide
Wild-type	(R)-, 25% e.e.	(R)-, 71% e.e.
Asn173Ser	(S)-, 12% e.e.	n.d.
Ser174Cys	(R)-, 37% e.e.	(R)-, 48% e.e.
Phe52Val	(S)-, 32% e.e.	Racemic
Phe52Arg	(R)-, 38% e.e.	n.d.
Phe52Leu	(R)-, 24% e.e.	(R)-, 67% e.e.

n.d. = not determined.