Wild-type His1 gene in the context of a histone gene repeat unit.
Wild-type His2A gene in the context of a histone gene repeat unit.
Wild-type His2B gene in the context of a histone gene repeat unit.
Wild-type His3 gene in the context of a histone gene repeat unit.
Mutated His4 gene (amino acid replacement K16Q), in the context of a histone gene repeat unit.
Contains three copies of the histone gene repeat unit (each repeat contains one copy of each of His1, His2A, His2B, His3 and His4). Each copy of the His4 gene has been mutated to contain the amino acid replacement K16Q.