Role of Conserved Histidines in Zinc Selectivity and Structural Integrity of Sorghum Metallothionein SbMT4
SbMT4 functions as a zinc-specific metallothionein whose conserved histidine residues are essential for selective Zn binding, proper protein folding, and limiting cadmium incorporation, although altering these residues does not significantly change whole-plant metal accumulation, when expressed ectopically.