– STAT, R-SMAD, NF-κB, Notch, TUBBY, NFAT Structural Transcription factors are often classified based on the sequence similarity and hence the tertiary structure of their DNA-binding domains: 1 Superclass: Basic Domains 1.1 Class: Leucine zipper factors (bZIP) 1.1.1 Family: AP-1(-like) components; includes (c-Fos/c-Jun) 1.1.2 Family: CREB 1.1.3 Family: C/EBP-like factors 1.1.4 Family: bZIP / PAR 1.1.5 Family: Plant G-box binding factors 1.1.6 Family: ZIP only 1.2 Class: Helix-loop-helix factors (bHLH) 1.2.1 Family: Ubiquitous (class A) factors 1.2.2 Family: Myogenic transcription factors (MyoD) 1.2.3 Family: Achaete-Scute 1.2.4 Family: Tal/Twist/Atonal/Hen 1.3 Class: Helix-loop-helix / leucine zipper factors (bHLH-ZIP) 1.3.1 Family: Ubiquitous bHLH-ZIP factors; includes USF (USF1, USF2); SREBP (SREBP) 1.3.2 Family: Cell-cycle controlling factors; includes c-Myc 1.4 Class: NF-1 1.4.1 Family: NF-1 (A, B, C, X) 1.5 Class: RF-X 1.5.1 Family: RF-X (1, 2, 3, 4, 5, ANK) 1.6 Class: bHSH 2 Superclass: Zinc-coordinating DNA-binding domains 2.1 Class: Cys4 zinc finger of nuclear receptor type 2.1.1 Family: Steroid hormone receptors 2.1.2 Family: Thyroid hormone receptor-like factors 2.2 Class: diverse Cys4 zinc fingers 2.2.1 Family: GATA-Factors 2.3 Class: Cys2His2 zinc finger domain 2.3.1 Family: Ubiquitous factors, includes TFIIIA, Sp1 2.3.2 Family: Developmental / cell cycle regulators; includes Krüppel 2.3.4 Family: Large factors with NF-6B-like binding properties 2.4 Class: Cys6 cysteine-zinc cluster 2.5 Class: Zinc fingers of alternating composition 3 Superclass: Helix-turn-helix 3.1 Class: Homeo domain 3.1.1 Family: Homeo domain only; includes Ubx 3.1.2 Family: POU domain factors; includes Oct 3.1.3 Family: Homeo domain with LIM region 3.1.4 Family: homeo domain plus zinc finger motifs 3.2 Class: Paired box 3.2.1 Family: Paired plus homeo domain 3.2.2 Family: Paired domain only 3.3 Class: Fork head / winged helix 3.3.1 Family: Developmental regulators; includes forkhead 3.3.2 Family: Tissue-specific regulators 3.3.3 Family: Cell-cycle controlling factors 3.3.0 Family: Other regulators 3.4 Class: Heat Shock Factors 3.4.1 Family: HSF 3.5 Class: Tryptophan clusters 3.5.1 Family: Myb 3.5.2 Family: Ets-type 3.5.3 Family: Interferon regulatory factors 3.6 Class: TEA ( transcriptional enhancer factor) domain 3.6.1 Family: TEA (TEAD1, TEAD2, TEAD3, TEAD4) 4 Superclass: beta-Scaffold Factors with Minor Groove Contacts 4.1 Class: RHR (Rel homology region) 4.1.1 Family: Rel/ankyrin; NF-kappaB 4.1.2 Family: ankyrin only 4.1.3 Family: NFAT (Nuclear Factor of Activated T-cells) (NFATC1, NFATC2, NFATC3) 4.2 Class: STAT 4.2.1 Family: STAT 4.3 Class: p53 4.3.1 Family: p53 4.4 Class: MADS box 4.4.1 Family: Regulators of differentiation; includes (Mef2) 4.4.2 Family: Responders to external signals, SRF (serum response factor) () 4.4.3 Family: Metabolic