Final answer:
RNA polymerase II forms the preinitiation complex in eukaryotic transcription, with the binding site typically being a TATA box sequence motif. TBP and TFIID recognize the TATA box and are involved in the assembly of the preinitiation complex.
Step-by-step explanation:
The preinitiation complex in eukaryotic transcription is formed by RNA polymerase II. This complex is responsible for initiating transcription by binding to the promoter region of a gene. The binding site for the preinitiation complex is typically a TATA box sequence motif on the DNA, which is recognized by the TATA-binding protein (TBP) and transcription initiation factor IID (TFIID).