Fig. 6

PirXI activity in the presence of Ca²⁺ and Mn²⁺. The activities of wild-type enzyme (green line) and the variant V270A–A273G (orange line) on 100 mM xylose were measured in the presence of a mixture of 1 mM Ca²⁺ and various concentrations of Mn²⁺. The data represent the average values from duplicate measurements and the error bars represent standard deviations