  Motivated by recent experiments we consider transport across an interacting
magnetic impurity coupled to the Majorana zero mode (MZM) observed at the
boundary of a topological superconductor (SC). In the presence of a finite
tunneling amplitude we observe hybridization of the MZM with the quantum dot,
which is manifested by a half-integer zero-bias conductance $G_0=e^2/2h$
measured on the metallic contacts. The low-energy feature in the conductance
drops abruptly by crossing the transition line from the topological to the
non-topological superconducting regime. Differently from the in-gap
Yu-Shiba-Rosinov-like bound states, which are strongly affected by the on-site
impurity Coulomb repulsion, we show that the MZM signature in the conductance
is robust and persists even at large values of the interaction. Interestingly,
the topological regime is characterized by a vanishing Fano factor, $F=0$,
induced by the MZM. Combined measurements of the conductance and the shot noise
in the experimental set-up presented in the manuscript allow to detect the
topological properties of the superconducting wire and to distinguish the
low-energy contribution of a MZM from other possible sources of zero-bias
anomaly. Despite being interacting the model is exactly solvable, which allows
to have an exact characterization of the charge transport properties of the
junction.
