7mi2 | pdb_00007mi2
Seb1-G476S RNA binding domain
Structural highlights
Function[SEB1_SCHPO] Involved in the processing of pol II transcripts.[1] Publication Abstract from PubMedThe system of long noncoding RNA (lncRNA)-mediated transcriptional interference that represses fission yeast phosphate homoeostasis gene pho1 provides a sensitive readout of genetic influences on cotranscriptional 3'-processing and termination and a tool for discovery of regulators of this phase of the Pol2 transcription cycle. Here, we conducted a genetic screen for relief of transcriptional interference that unveiled a mechanism by which Pol2 termination is enhanced via a gain-of-function mutation, G476S, in the RNA-binding domain of an essential termination factor, Seb1. The genetic and physical evidence for gain-of-function is compelling: 1) seb1-G476S de-represses pho1 and tgp1, both of which are subject to lncRNA-mediated transcriptional interference; 2) seb1-G476S elicits precocious lncRNA transcription termination in response to lncRNA 5'-proximal poly(A) signals; 3) seb1-G476S derepression of pho1 is effaced by loss-of-function mutations in cleavage and polyadenylation factor (CPF) subunits and termination factor Rhn1; 4) synthetic lethality of seb1-G476S with pho1 derepressive mutants rpb1-CTD-S7A and aps1 is rescued by CPF/Rhn1 loss-of-function alleles; and 5) seb1-G476S elicits an upstream shift in poly(A) site preference in several messenger RNA genes. A crystal structure of the Seb1-G476S RNA-binding domain indicates potential for gain of contacts from Ser476 to RNA nucleobases. To our knowledge, this is a unique instance of a gain-of-function phenotype in a eukaryal transcription termination protein. Genetic screen for suppression of transcriptional interference identifies a gain-of-function mutation in Pol2 termination factor Seb1.,Schwer B, Garg A, Jacewicz A, Shuman S Proc Natl Acad Sci U S A. 2021 Aug 17;118(33). pii: 2108105118. doi:, 10.1073/pnas.2108105118. PMID:34389684[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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