Term Name:	RNA polymerase II CTD heptapeptide repeat Y1 phosphatase activity
Synonyms:	RNA polymerase II C-terminal domain Y1 phosphatase activity
Definition:	Catalysis of the reaction: RNA polymerase II large subunit CTD heptapeptide repeat--phospho-L-tyrosine (consensus YSPTSPS)(position 1) + H2O = RNA polymerase II large subunit + phosphate.
Ontology:	GO: Molecular Function [GO:0180004]    QuickGO    AmiGO