| Type: | Domain | Name: | SANT domain |
| Description: | The SANT domain is a motif of ~50 amino acids present in proteins involved in chromatin-remodelling and transcription regulation. This eukaryotic domain was identified in nuclear receptor co-repressors and named after switching-defective protein 3 (Swi3), adaptor 2 (Ada2), nuclear receptor co-repressor (N-CoR) and transcription factor (TF)IIIB []. Although SANT domains show remarkable sequence and structural similarity to the DNA-binding helix-turn-helix (HTH) domain of the myb-like tandem repeat, their function is not DNA binding. Instead, SANT domains are protein-protein interaction modules and some can bind to histone tails (e.g. in Ada2 and SMRT). The SANT domain has been proposed to function as a histone-interaction module that couples histone-tail binding to enzyme catalysis for the remodelling of nucleosomes [, ].SANT domains are found in combination with other domains, such as the SWIRM domain (see , ), the ZZ-type zinc finger (see , ), the C2H2-type zinc finger (see , ), the GATA-type zinc finger (see , ), the MPN-domain and DEAH ATP-helicase domain (see ). The 3-dimensional structure of the SANT domain forms three alpha helices [] similar to the DNA-binding myb-type HTH domain. Because of the strong resemblance, the SANT domain can also be detected as a myb-like "DNA-binding" domain. Most SANT domains have acidic amino acids at the start of helix 2 and in helix 3, while myb-like DNA-binding domains have more positively charged residues, in particular in their third 'recognition' helix. The bulky aromatic and hydrophobic residues in the centre of helix 3 that are incompatible with DNA contacts of myb-like DNA-binding domains form another distinguishing property of SANT domains. | Short Name: | SANT_dom |
