The eukaryotic RPB11 subunit of RNA polymerase (RNAP), as well as its archaeal (L subunit) and bacterial (alpha subunit) counterparts, is involved in the assembly of RNAP subunits. RNAP is a large multi-subunit complex responsible for the synthesis of RNA. It is the principal enzyme of the transcription process, and is a final target in many regulatory pathways that control gene expression in all living cells. At least three distinct RNAP complexes are found in eukaryotic nuclei: RNAP I, RNAP II, and RNAP III, for the synthesis of ribosomal RNA precursor, mRNA precursor, and 5S and tRNA, respectively. A single distinct RNAP complex is found in prokaryotes and archaea, which may be responsible for the synthesis of all RNAs. The assembly of the two largest eukaryotic RNAP subunits that provide most of the enzyme's catalytic functions depends on the presence of RPB3/RPB11 heterodimer subunits. This is also true for the archaeal (D/L subunits) and bacterial (alpha subunit) counterparts.
Comment:The yeast RNAP II RPB11/RPB3 heterodimer (L/D heterodimer in archaea), together with RPB10 (N) and RPB12 (P), anchors the two largest subunits, RPB1 (A'/A") and RPB2 (B), stabilizing their association.
Structure:1I50_K; Saccharomyces cerevisiae RNAP II RPB11 subunit heterodimerizes with RPB3 subunit (1I50_C), defined using 3.5A contacts - View structure with Cn3D
Comment:RPB11 (L) interfaces with the RPB11-like subdomain of RPB3 (D).