... subunit, analysis of the interaction of the three subunits with the yeast two-hybrid system, and reconstitution of the enzyme activityby co-expression of recombinant CHLD, CHLH and CHLI. Plant ... stimulated. The discovery that another pro-tein, Gun4, can both stimulate Mg chelatase and bindMgP [12,25] adds another layer of complexity to both the regulation of chlorophyll biosynthesis, and the availability ... 4532–4539 ª 2005 FEBSthen depleted (rate constants of 11.9 ± 0.5 s)1 and 11.8 ± 0.5 s)1, respectively), and the decay of the intermediate species coincides with the evolution of magnesium deuteroporphyrin...