Transcription factors of the basic helix-loop-helix zipper (bHLH-ZIP) family contain a basic domain, used for DNA binding, and HLH and ZIP domains, both used for oligomerization. TFEB was isolated from a human B-cell cDNA library using a binding sequence from the adenovirus major late promoter. This transcription factor probably binds to the USF/MLTF site and probably recognizes E-box sequences in the heavy-chain immunoglobulin enhancer.