FEATURES

FAMILY

DESCRIPTION

Also known as RPA2_YEAST, RPA135, RPA2, RRN2, SRP3. DNA-dependent RNA polymerases catalyze the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Component of RNA polymerase I (Pol I) which synthesizes ribosomal RNA precursors. Besides, RNA polymerase I has intrinsic RNA cleavage activity. RPA190 and RPA135 both contribute to the polymerase catalytic activity and together form the Pol I active center. In addition, subunit RPA12 contributes a catalytic zinc ribbon that is required for RNA cleavage by Pol I. A single stranded DNA template strand of the promoter is positioned within the central active site cleft of Pol I. A bridging helix emanates from RPA190 and crosses the cleft near the catalytic site and is thought to promote translocation of Pol I by acting as a ratchet that moves the RNA-DNA hybrid through the active site by switching from straight to bent conformations at each step of nucleotide addition. Component of the RNA polymerase I (Pol I) complex consisting of 14 subunits: RPA135, RPA190, RPC40, RPA14, RPB5, RPO26, RPA43, RPB8, RPA12, RPB10, RPC19, RPC10, RPA49 and RPA34. The complex is composed of a horseshoe-shaped core containing ten subunits (RPA135, RPA190, RPB5, RPO26, RPB8, RPB10, RPC10, RPA12, RPC19 and RPC40) where RPA135 and RPA190 form the DNA-binding cleft. Outside of the core, RPA14 and RPA43 form the stalk that mediates interactions with transcription initiation factors and newly synthesized RNA.

EXTERNAL LINKS

RPA135

Mutations

Mutation(s) distribution

Mutations table