InterPro domain: IPR038510

This superfamily consists of several eukaryotic transcription initiation Spt4 proteins. Three transcription-elongation factors Spt4, Spt5, and Spt6 are conserved among eukaryotes and are essential for transcription via the modulation of chromatin structure. Spt4 and Spt5 are tightly associated in a complex, while the physical association of the Spt4-Spt5 complex with Spt6 is considerably weaker. It has been demonstrated that Spt4, Spt5, and Spt6 play roles in transcription elongation in both yeast and humans including a role in activation by Tat. It is known that Spt4, Spt5, and Spt6 are general transcription-elongation factors, controlling transcription both positively and negatively in important regulatory and developmental roles [ 1 ].

1. Control of eukaryotic transcription elongation. Genome Biol. 2, REVIEWS1006