Domain

Transcription factor, SBP-box (IPR004333)

Short name: Transcpt_factor_SBP-box

Domain relationships

None.

Description

SBP (for SQUAMOSA-pROMOTER BINDING PROTEIN) domain is a sequence specific DNA-binding domain found in plant proteins [PMID: 8569690]. Members of family probably function as transcription factors involved in the control of early flower development [PMID: 8569690]. They share a highly conserved DNA-binding domain that contains two zinc-binding sites. Among the 11 possible ligands for the zinc atoms that are conserved in the SBP zinc finger, only 8 are used. The SBP zinc finger follows the general pattern C-x4-C-x16-C-x2-[HC]-x15-C-x2-C-x3-H-x11-C. Three other histidines are well conserved but not involved in zinc binding [PMID: 8569690, PMID: 15001351].

In vitro experiments show that the SBP zinc finger preferentially binds the consensus sequence -TNCGTACAA- [PMID: 10524240]. However, little is known of the physiological functions of these putative transcriptional regulators beyond their ability to bind DNA.

The solution structure of the SBP zinc finger has been solved [PMID: 15001351]. The first four Cys or His coordinate one zinc ion and the last four coordinate the other. It can be viewed as two structural subdomains, each subdomain containing a single zinc-binding pocket. The N-terminal subdomain consists of two short alpha helices whereas the C-terminal one contains a three-stranded antiparallel beta-sheet.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0003677 DNA binding

Cellular Component

GO:0005634 nucleus

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE profiles
SUPERFAMILY
GENE3D
Pfam