FKBP52 can isomerize selected prolyl bonds in Tau through its first FK506 domain.

Its peptidyl-prolyl isomerase activity is not linked to its capacity to oligomerize Tau.

A novel molecular interaction between the Tau PHF6 peptide and the two first domains of FKBP52 is characterized.

This physical interaction could stabilize an aggregation-prone conformation of Tau.