Binds preferentially double-stranded telomeric repeats 5'-TTTAGGG-3', but can also bind to the single G-rich and C-rich telomeric strand. Forms a homodimer and heterodimers. Localized to the nucleolus during interphase. Expressed in leaves. HTH myb-type domain confers double-stranded telomeric DNA-binding while the H15 domain is involved in non-specific DNA-protein interaction and multimerization. Belongs to the histone H1/H5 family. SMH subfamily.