Substitutions in RNA-binding protein Hrp1 map a potential interaction surface with the yeast RNA polymerase II elongation complex.

ABSTRACT: Anti-termination factors for eukaryotic RNA polymerase II (RNAP II) that are released upon binding sequences in the terminator of nascent transcripts were proposed almost 40 years ago but few candidates have been found. Here we report genetic evidence that the yeast nuclear RNA-binding protein Hrp1, also known as Nab4 and CF1B, acts as an RNAP II anti-termination factor. A Lys to Glu substitution at residue 9 (K9E) of the Rpb3 subunit of RNAP II causes readthrough of Nrd1-Nab3-Sen1-dependent (NNS) terminators and cold-sensitive growth, as does Asp but not Ala, Met, Arg, or Gln substitution. These allele-specific phenotypes and the location of Rpb3-K9 suggests substitution with Glu or Asp stabilizes binding of an anti-termination factor via a salt bridge. A genome-wide selection for suppres

SUBMITTER: Wang M 

PROVIDER: S-EPMC12247754 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature