There certainly is still a BATFE and they still do the same jobs. They were moved from the Treasury Department to the Justice Department (not DHS).
The original agency was the Alcohol Tax Division (ATD) of the Internal Revenue Service because their job was to collect taxes on alcohol. They first became noted (or notorious) as the "revenooers", charged with busting up illegal stills, an occupation with about the same level of risk as patrolling Baghdad.
When Congress enacted a tobacco tax, they were named the Alcohol and Tobacco Tax Division (ATTD) of the IRS. In the meantime, they had also been given responsibility for enforcement of the federal gun laws (the NFA and FFA), because those laws were snuck through as "tax" laws. But it was not until they became a bureau (higher up on the organizational chart than a mere IRS division) that "Firearms" was added to the name and they became the Bureau of Alcohol, Tobacco, and Firearms. Still later, they were given responsibility for enforcing federal explosives laws and investigating crimes involving explosives, and that, too, was added on.
The move to Justice was something of a compromise. Treasury didn't really want the heat they brought, and many lawmakers wanted to abolish BATFE altogether and transfer their duties to the FBI, something the FBI didn't want either. So they were moved into Justice, as rather uncomfortable bedfellows with the FBI, but without being part of that agency. The official line, of course, is that everyone is just fine and very happy to be working together to enforce the laws and protect the citizens. Of course all those intelligence and crime fighting agencies get along well and cooperate fully in guarding our nation. (If you believe that, I have this ocean front lot in Kansas...)
Jim