Transcription factors are essential proteins that regulate gene expression by binding to specific DNA sequences and modulating the transcriptional initiation of target genes. These proteins often contain various types of domains that enable them to perform their regulatory functions. DNA-binding domains found in transcription factors include: 1) The Basic Helix-Loop-Helix (bHLH). This domain family is characterized by a conserved helix-loop-helix structure. bHLH transcription factors dimerize and bind to specific DNA sequences termed E-boxes. Examples include MyoD and Myc; 2) Zinc Finger. Zinc finger domains coordinate a zinc ion and interact with DNA. The C2H2 zinc finger is the most common type, present in proteins like Sp1, which regulates gene expression in many biological processes; 3) Homeodomain. Homeodomain-containing proteins are crucial for development and pattern formation. HOX genes, such as HOXA, specify body segment identity in animals; 4) Leucine Zipper (bZIP): bZIP domains facilitate dimerization and DNA binding. The transcription factors c-Jun and c-Fos, components of the AP-1 complex, contain bZIP domains and regulate gene expression in response to various stimuli; 5) Winged Helix (Forkhead). Forkhead domain proteins, such as FOXO3, are involved in a wide range of cellular processes, including metabolism and longevity regulation. Transactivation Domains (TADs) are responsible for activating gene transcription by interacting with coactivators and components of the transcriptional machinery. For example, p53 contains a TAD that activates various target genes involved in cell cycle regulation and DNA repair. Some transcription factors, like activator protein-1 (AP-1) subunits, possess proline-rich motifs that similarly facilitate protein-protein interactions and transcriptional activation. Other domains found in transcription factors act as repressor domains. For example, the POZ domain is found in transcription factors like BCL6, and is involved in transcriptional repression, mediating protein-protein interactions, and corepressor recruitment. The Krüppel-associated box (KRAB) domain-containing zinc finger proteins (KZFPs) often also act as transcriptional repressors, recruiting corepressors to inhibit gene expression. Other domains found in transcription factors act as modulatory domains. For example, SH2 domains are present in proteins like STATs (Signal Transducers and Activators of Transcription). They recognize phosphorylated tyrosine residues and are essential for signal transduction and gene activation in response to extracellular signals. SH3 domains mediate protein-protein interactions. They are involved in various cellular processes, including transcriptional regulation. For example, some isoforms of C/EBP contain an SH3 domain, such as C/EBPε (also known as C/EBPβ-2) and C/EBPζ (also known as CHOP). Other domains in transcription factors act as chromatin-interacting domains. Bromodomain-containing proteins, like BRD4 for example, recognize acetylated histones and play a crucial role in chromatin remodelling and gene regulation, whilst chromodomain-containing proteins, such as HP1 (Heterochromatin Protein 1), recognize specific histone marks and are involved in chromatin organization and gene silencing. Finally, additional domains found in transcription factors mediate protein-protein interactions. TET (TATA-Box-Associated Factor) domains for example interact with other components of the transcription machinery, such as TBP (TATA-binding protein), and are involved in transcriptional initiation, whilst TAF (TBP-Associated Factor) domains, part of the TFIID complex, play a role in protein-protein interactions necessary for transcriptional initiation. We provide a wide product range of research tools for investigating transcription factor domain families, including Estrogen Receptor alpha antibodies, c-Myc antibodies, c-Jun antibodies, c-Jun ELISA Kits, and FOXO1A ELISA Kits. Explore our full transcription factor domain families product range below and discover more, for less. Alternatively, you can explore our Zinc Finger, HLH & Leucine Zipper, and Developmental Families product ranges.