RNAP_I_Rpa43_N: Rpa43, N-terminal ribonucleoprotein (RNP) domain. Rpa43 is a subunit of eukaryotic RNA polymerase (RNAP) I that is homologous to Rpb7 of eukaryotic RNAP II, Rpc25 of eukaryotic RNP III, and RpoE of archaeal RNAP. Rpa43 has two domains, an N-terminal RNP domain and a C-terminal oligonucleotide-binding (OB) domain. Rpa43 heterodimerizes with Rpa14 and this heterodimer has genetic and biochemical characteristics similar to those of the Rpb7/Rpb4 heterodimer of RNAP II. In addition, the Rpa43/Rpa14 heterodimer binds single-stranded RNA, as is the case for the Rpb7/Rpb4 and the archaeal E/F complexes. The position of Rpa43/Rpa14 in the three-dimensional structure of RNAP I is similar to that of Rpb4/Rpb7, which forms an upstream interface between the C-terminal domain of Rpb1 and the transcription factor IIB (TFIIB), recruiting pol II to the pol II promoter. Rpb43 binds Rrn3, an rDNA-specific transcription factor, functionally equivalent to TFIIB, involved in recruiting RNAP I to the pol I promoter.
Feature 1:putative Rpa14 interaction site [polypeptide binding site]
Evidence:
Comment:Based on the interaction site of other members of this family with other RNAP subunits. This is the surface by which Rpb7 of eukaryotic RNAP II, Rpc25 of eukaryotic RNAP III, and RpoE (subunit E) of archaeal RNAP heterodimerize with another RNAP subunit (Rpb7 to Rpb4, Rpc25 to Rpc17, and RpoE to RpoF).
Jiyao W et al.(2023). "The conserved domain database in 2023.",