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 in the context of a histone gene repeat unit; contains a R92A amino acid replacement (mutation of a residue known to normally undergo post-translational modification).