Figure 6: Analysis of atTic40 Deletion Mutants

The data illustrate the ability of different domain-deletion mutants of atTic40 to complement the atTic40 knockout mutant, tic40, and in so doing shed light on the relative importance of different atTic40 domains (TM: transmembrane domain; Sti1: Sti1 or Hip/Hop domain; TPR: tetratricopeptide repeat domain). The results show that the TM and Sti1 domains are essential for atTic40 functionality, and that the larger ΔTPR deletion results in a "dominant-negative" phenotype that is even more severe than that of the untransformed tic40 mutant. Panel A shows typical 10-day-old in vitro-grown seedlings from two representative tic40 mutant lines carrying the indicated constructs, alongside wild-type (WT) and untransformed tic40 controls. Panel B shows plastid ultrastructure in cotyledons of 10-day-old albino ΔTPR seedlings (i.e., tic40 mutant plants expressing the ΔTPR construct). Two representative organelles are shown (panels i and ii), alongside typical wild-type and tic40 control chloroplasts. The scale-bar shows 1 μm. Taken from J. Biol. Chem., 2007, 282: 21404-21414.