Complex sentence: It is especially unique in that it contains 10 Se-Cys residues, which are split into two domains, a longer N-terminal domain that contains 1 Se-Cys, and a shorter C-terminal domain that contains 9 Se-Cys.
Split into simpler sentences: It is especially unique in that it contains 10 Se-Cys residues, which are split into two domains. A longer N-terminal domain that contains 1 Se-Cys, and a shorter C-terminal domain that contains 9 Se-Cys.