Rpa43 and its partners in the yeast RNA polymerase I transcription complex

An Rpa43/Rpa14 stalk protrudes from RNA polymerase I (RNAPI), with homology to Rpb7/Rpb4 (RNAPII), Rpc25/Rpc17 (RNAPIII) and RpoE/RpoF (archaea). In fungi and vertebrates, Rpa43 contains hydrophilic domains forming about half of its size, but these domains lack in Schizosaccharomyces pombe and most other eukaryote lineages. In Saccharomyces cerevisiae, they can be lost with little or no growth effect, as shown by deletion mapping and by domain swapping with fission yeast, but genetically interact with rpa12D, rpa34D or rpa49D, lacking non-essential subunits important for transcript elongation. Two-hybrid data and other genetic evidence suggest that Rpa43 directly bind Spt5, an RNAPI elongation factor also acting in RNAPII-dependent transcription, and may also interact with the nucleosomal chaperone Spt6. Structured summary of protein interactions: RPA43 physically interacts with SPT6 by two hybrid (View interaction) HMO1 and SPT6 colocalize by fluorescence microscopy (View interaction) RPA43 physically interacts with RPA14 by two hybrid (View interaction) RPA43 physically interacts with SPT5 by two hybrid (View interaction) HMO1 and SPT5 colocalize by fluorescence microscopy (View interaction) (C) 2011 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.