dbus-x11 software package provides simple interprocess messaging system (X11 deps), you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install dbus-x11
dbus-x11 is installed in your system.
Make ensure the dbus-x11 package were installed using the commands given below,
$ sudo dpkg-query -l | grep dbus-x11 *
You will get with dbus-x11 package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | X Window System software |
| Package | dbus-x11 |
| Version | 1.10.6-1ubuntu3.1 [amd64, i386 |
| Description | simple interprocess messaging system (X11 deps) |
| Sub Section | X138 |