Table I. Kinetic properties of the carboxylase activity of Rubisco purified from the C. reinhardtii mutants expressing its own (CrRbcS1) small subunit as well as the mesophyll (NtRbcS-M) and the trichome (NtRbcS-T) small subunit from tobacco.

The means ± sd of three independent preparations are shown. For each parameter, asterisks indicate significant differences between enzymes according to a Kruskal-Wallis test (P < 0.05, n = 3) followed by a Tukey post-hoc test.

	Km (µm)	Vmax (µmol/min/mg)	Activity in the Presence of O2 (% of the Maximum Activity)a
CrRbcS1	35.1 ± 2.9	1.84 ± 0.13	73.9 ± 3.5
NtRbcS-M	26.8 ± 1.6*	1.60 ± 0.06*	74.0 ± 3.0
NtRbcS-T	38.4 ± 5.1	1.96 ± 0.15	71.9 ± 3.9

^aActivity in the presence of O₂ was calculated as a percentage of the maximum activity measured in the presence of N₂ (see “Materials and Methods”).