Background
Piggy backing off the question about two United State political bodies conducting an investigation, someone made a comment that the a U.S. attorney is always part of the DoJ. I understand that in the typical case, a lawyer (usually) represents someone who is the entity pressing charges. But I'm not sure if the same rules necessarily apply to U.S. attorneys of the Federal Government.
Question
When a U.S. Attorney files charges acting in his office, does this automatically mean that the DoJ itself is the party filing a charge?