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

ABSTRACT: Antitermination 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 antitermination 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 in a reporter gene and cold-sensitive growth, as does an Asp but not an Ala, Met, Arg, or Gln substitution. These allele-specific phenotypes and the location of Rpb3-K9 suggest substitution with Glu or Asp stabilizes binding of an antitermination factor via a salt bridge. A genome-wide

SUBMITTER: Wang M 

PROVIDER: S-EPMC12671597 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature