RNA polymerase II CTD heptapeptide repeat Y1 phosphatase activity
rna polymerase ii ctd heptapeptide repeat y1 phosphatase activity
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.