The FACT or facilitator of chromatin transcription complex binds to and alters the properties of nucleosomes. This family represents the N-terminal lobe of the NTD, or N-terminal domain, and acts as a protein-protein interaction domain presumably with partners outside of the FACT complex [1]. Knockout of the whole NTD domain, 1-450 residues in UniProt:P32558, in yeast serves to tender the cells sensitive to DNA replication stress but is not lethal. The C-terminal half of NTD is structurally similar to aminopeptidases, and the most highly conserved surface residues line a cleft equivalent to the aminopeptidase substrate-binding site, family peptidase_M24, Pfam:PF00557 [1].

1: Structural and functional analysis of the Spt16p N-terminal domain reveals overlapping roles of yFACT subunits. VanDemark AP, Xin H, McCullough L, Rawlins R, Bentley S, Heroux A, Stillman DJ, Hill CP, Formosa T; J Biol Chem. 2008;283:5058-5068. PMID:18089575