  We propose a platform for universal quantum computation that uses
conventional $s$-wave superconducting leads to address a topological qubit
stored in spatially separated Majorana bound states in a multi-terminal
topological superconductor island. Both the manipulation and read-out of this
"Majorana superconducting qubit" are realized by tunnel couplings between
Majorana bound states and the superconducting leads. The ability of turning on
and off tunnel couplings on-demand by local gates enables individual qubit
addressability while avoiding cross-talk errors. By combining the scalability
of superconducting qubit and the robustness of topological qubits, the Majorana
superconducting qubit may provide a promising and realistic route towards
quantum computation.
