Fcp1 directly recognizes the C-terminal domain (CTD) and interacts with a site on RNA polymerase II distinct from the CTD.

ABSTRACT: Fcp1 is an essential protein phosphatase that hydrolyzes phosphoserines within the C-terminal domain (CTD) of the largest subunit of RNA polymerase II (Pol II). Fcp1 plays a major role in the regulation of CTD phosphorylation and, hence, critically influences the function of Pol II throughout the transcription cycle. The basic understanding of Fcp1-CTD interaction has remained ambiguous because two different modes have been proposed: the "dockingsite" model versus the "distributive" mechanism. Here we demonstrate biochemically that Fcp1 recognizes and dephosphorylates the CTD directly, independent of the globular non-CTD part of the Pol II structure. We point out that the recognition of CTD by the phosphatase is based on random access and is not driven by Pol II conformation. Results from

SUBMITTER: Suh MH 

PROVIDER: S-EPMC1297677 | biostudies-literature | 2005 Nov

REPOSITORIES: biostudies-literature