/usr/share/mate/ is in ubuntu-mate-default-settings 18.04.17.
This file is owned by root:root, with mode 0o755.
..
/usr/share/mate-panel/layouts/
/usr/share/mate-panel/layouts/contemporary.layout
/usr/share/mate-panel/layouts/eleven.dock
/usr/share/mate-panel/layouts/eleven.layout
/usr/share/mate-panel/layouts/familiar.layout
/usr/share/mate-panel/layouts/mutiny.layout
/usr/share/mate-panel/layouts/mutiny.panel
/usr/share/mate-panel/layouts/netbook.layout
/usr/share/mate-panel/layouts/netbook.panel
/usr/share/mate-panel/layouts/pantheon.dock
/usr/share/mate-panel/layouts/pantheon.layout
/usr/share/mate-panel/layouts/redmond.layout
/usr/share/mate-panel/layouts/ubuntu-mate.layout
/usr/share/mate/applications/
/usr/share/mate/applications/compton.desktop
/usr/share/mate/applications/debian-uxterm.desktop
/usr/share/mate/applications/debian-xterm.desktop
/usr/share/mate/applications/defaults.list
/usr/share/mate/applications/display-im6.desktop
/usr/share/mate/applications/display-im6.q16.desktop
/usr/share/mate/applications/gnome-language-selector.desktop
/usr/share/mate/applications/gtkhash.desktop
/usr/share/mate/applications/kde-Kantiword-Installer.desktop
/usr/share/mate/applications/org.mate-desktop.mate-eiciel.desktop
/usr/share/mate/applications/software-properties-gtk.desktop
/usr/share/mate/applications/tilda.desktop
/usr/share/mate/autostart/
/usr/share/mate/autostart/caja-dropbox-autostart.desktop
/usr/share/mate/autostart/indicator-application.desktop
/usr/share/mate/autostart/indicator-messages.desktop
/usr/share/mate/autostart/indicator-power.desktop
/usr/share/mate/autostart/indicator-session.desktop
/usr/share/mate/autostart/indicator-sound.desktop
/usr/share/mate/autostart/ubuntu-mate-settings-overlay.desktop