Ssu72 phosphatase-dependent erasure of phospho-Ser7 marks on the RNA polymerase II C-terminal domain is essential for viability and transcription termination

David W. Zhang, Amber L. Mosley, Sreenivasa R. Ramisetty, Juan B. Rodríguez-Molina, Michael P. Washburn, Aseem Z. Ansari

Research output: Contribution to journalArticle

66 Scopus citations


The C-terminal domain (CTD) of the largest subunit of RNA polymerase II (Pol II) serves an important role in coordinating stage-specific recruitment and release of cellular machines during transcription. Dynamic placement and removal of phosphorylation marks on different residues of a repeating heptapeptide (YSPTSPS) of the CTD underlies the engagement of relevant cellular machinery. Whereas sequential placement of phosphorylation marks is well explored, genome-wide engagement of phosphatases that remove these CTD marks is poorly understood. In particular, identifying the enzyme that erases phospho- Ser7 (Ser7-P) marks is especially important, because we find that substituting this residue with a glutamate, a phosphomimic, is lethal. Our observations implicate Ssu72 as a Ser7-P phosphatase. We report that removal of all phospho-CTD marks during transcription termination is mechanistically coupled. An inability to remove these marks prevents Pol II from terminating efficiently and will likely impede subsequent assembly into the pre-initiation complex.

Original languageEnglish (US)
Pages (from-to)8541-8551
Number of pages11
JournalJournal of Biological Chemistry
Issue number11
StatePublished - Mar 9 2012


ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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