Component of the FACT complex, a general chromatin factor that acts to reorganize nucleosomes. The FACT complex is involved in multiple processes that require DNA as a template such as mRNA elongation, DNA replication and DNA repair. During transcription elongation the FACT complex acts as a histone chaperone that both destabilizes and restores nucleosomal structure. It facilitates the passage of RNA polymerase II and transcription by promoting the dissociation of one histone H2A-H2B dimer from the nucleosome, then subsequently promotes the reestablishment of the nucleosome following the passage of RNA polymerase II. The FACT complex is probably also involved in phosphorylation of 'Ser-392' of p53/TP53 via its association with CK2 (casein kinase II). Interacts with MYOG (via C-terminal region) (By similarity). Component of the FACT complex, a stable heterodimer of SSRP1 and SUPT16H (PubMed:10421373). Also a component of a CK2-SPT16-SSRP1 complex which forms following UV irradiation, composed of SSRP1, SUPT16H, CSNK2A1, CSNK2A2 and CSNK2B (PubMed:11239457, PubMed:12393879). Interacts with NEK9 (PubMed:14660563). Binds to histone H2A-H2B (PubMed:10421373). Identified in a centromere complex containing histones H2A, H2B and H4, and at least CENPA, CENPB, CENPC, CENPT, CENPN, HJURP, SUPT16H, SSRP1 and RSF1 (PubMed:27499292). Interacts with GTF2E2 (PubMed:10792464). (Microbial infection) Interacts with Herpes simplex virus 1 (HHV-1) protein ICP22; this interaction relocalizes the FACT complex to viral genomes in infected cells. Colocalizes with RNA polymerase II on chromatin. Recruited to actively transcribed loci. Ubiquitous. The C-terminal Glu-rich acidic region is essential for FACT activity. ADP-ribosylated. ADP-ribosylation by PARP1 is induced by genotoxic stress and correlates with dissociation of FACT from chromatin. The disease may be caused by variants affecting the gene represented in this entry. Belongs to the peptidase M24 family. SPT16 subfamily. Although related to the peptidase M24 family, this protein lacks conserved active site residues suggesting that it may lack peptidase activity. Contaminating sequence. Potential poly-A sequence. Contaminating sequence. Potential poly-A sequence.