MATE by default is similar to a vanilla GNOME 2.x install. This means you won't get the Mint menu, etc. unless you install those separately, most likely by adding Mint repos to your system (but note this could potentially cause problems).
General information on how to install MATE can be found here. If you want to install Mint's version of it, you could try following the steps which will add the Mint repos to your sources list here.