obsolete cyclin-dependent protein tyrosine kinase activity true cyclin-dependent protein tyrosine kinase activity OBSOLETE. Catalysis of the reaction: ATP + a protein tyrosine = ADP + protein tyrosine phosphate. This reaction requires the binding of a regulatory cyclin subunit. GO:0097469 molecular_function pr 2013-02-19T12:42:11Z This term was made obsolete because it was added in error; the specific activity it refers to has never been observed.