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. Binds specifically to single-stranded DNA and RNA with highest affinity for nucleotides G and U. The FACT complex is required for expression of Hox genes. Component of the FACT complex, a stable heterodimer of dre4/spt16 and Ssrp. Interacts with CHD1 and TRL/GAGA. Colocalizes with RNA polymerase II on chromatin. Recruited to actively transcribed loci. Expressed at highest levels in nurse cells of the ovary. Abundant throughout oogenesis and embryogenesis, decreases during larval stages and increases again in pupae. Belongs to the SSRP1 family.