Necessary for efficient RNA polymerase II transcription elongation past template-encoded arresting sites. The arresting sites in DNA have the property of trapping a certain fraction of elongating RNA polymerases that pass through, resulting in locked ternary complexes. Cleavage of the nascent transcript by S-II allows the resumption of elongation from the new 3'-terminus.
Testis and ovary specific.
Belongs to the TFS-II family. Contains 1 TFIIS central domain. Contains 1 TFIIS N-terminal domain. Contains 1 TFIIS-type zinc finger.