Which of the following are notable elongation factors in eukaryotic transcription?

In the context of eukaryotic transcription, elongation factors play a crucial role in the process of mRNA synthesis. These factors are involved in the transition of RNA polymerase from the initiation phase into the elongation phase, helping to enhance the efficiency and accuracy of transcription.

The choice that states TATSF1, TF2S, and SPT 5 specifically highlights factors that are integral to the elongation phase of transcription. For instance, TATSF1 (Transcription Activator and Repression through TBP) is involved in facilitating the binding of RNA polymerase II during elongation. TF2S aids in the interaction between the RNA polymerase and the elongation complex, while SPT 5 is known to assist in stabilizing the elongation complex and improving RNA polymerase's processivity. Together, these factors help ensure that transcription proceeds smoothly and efficiently.

In comparison, other options list factors that either pertain more to initiation or do not specifically play significant roles in the elongation process. This distinction is essential to recognize as it underscores the specialized functions of different transcription factors within the eukaryotic transcription machinery.