Table 2.

Kinetic data for glutamylation activity of M. thermautotrophicus ND-GluRS for tRNA^Gln

Enzyme	KM (µM)	kcat (min−1)	kcat/KM (min−1/µM)
GluRS	2.1 ± 0.4	0.7 ± 0.1	0.3 ± 0.1
GluRS + GatDEa	2.4 ± 0.6	0.6 ± 0.1	0.3 ± 0.1
GluRS + BSAb	2.4 ± 0.5	0.6 ± <0.1	0.3 ± 0.1

Measurements were from three to four separate experiments. Standard deviations are reported. Reactions with M. thermautotrophicus ND-GluRS (50 nM) were carried out as described in the ‘Materials and Methods’ section at 37°C in the presence of excess ATP (4 mM), Glu (1 mM) and Asn (2 mM). The concentration of tRNA^Gln varied from 0.31 µM up to 15 µM.

^aGatDE (2.0 µM) or ^bBSA (2.0 µM) was added to the reaction mix.