Table 3. Catalytic activity of PaHSS, BvHSS and BvHSS variants.

The time-resolved production of HSP was quantified after the addition of 10 mM PUT dihydrochloride. Initial reaction velocities were determined from the linear fit to the initial data points of the progression curves.

Protein	T (K)	Initial velocity V 0 (mM min−1)
BvHSS wild type	310	0.34 ± 0.05
BvHSS D94N	310	0.20 ± 0.01
BvHSS D94K	310	0.17 ± 0.02
BvHSS W229F	310	0.0067 ± 0.0006
BvHSS E117Q	310	0.005 ± 0.001
BvHSS W229Y	310	0.0038 ± 0.0003
BvHSS wild type	298	0.108 ± 0.009
PaHSS wild type	298	0.037 ± 0.004
BvHSS E117K	310	<9 × 10−5 (inactive)
BvHSS E210A	310	<9 × 10−5 (inactive)
BvHSS E210K	310	<9 × 10−5 (inactive)
BvHSS E210Q	310	<9 × 10−5 (inactive)
BvHSS W229A	310	<9 × 10−5 (inactive)
BvHSS W229E	310	<9 × 10−5 (inactive)
BvHSS W229H	310	<9 × 10−5 (inactive)
BvHSS W229K	310	<9 × 10−5 (inactive)