['Vitamin B6 synthesis requires a functional Pdx1 assembly that is dodecameric in vivo. We have previously shown that mutation of a catalytic lysine in the plasmodial Pdx1 protein results in a protein that is both inactive and hexameric in vitro.', 'Static and dynamic light scattering, circular dichroism, co-purification and enzyme assays are used to investigate the role of a glycine conserved in all Pdx1 family members.', 'Static light scattering indicates that a glycine to alanine mutant is present as a hexamer in vitro. Subsequent circular dichroism experiments demonstrate that a significant change in secondary structure content is induced by this mutation. However, this mutant is still competent to bind and support Pdx2 activity.'] Is mobility of the conserved glycine 155 required for formation of the active plasmodial Pdx1 dodecamer?