In eukaryotes, different groups of proteins regulate transcription initiation. classify all of the transcription-associated proteins and protein components by their role in transcription.

Eukaryotes are organism known to having nucleus (containing genetic material) and organelles (e. g. the cell's powerhouse, mitochondria, golgi aparatus, ec.) enveloped by a membrane. They can be unicellular (single-celled organism) or multicellular (many-celled), containing tissues and different cell types.