Domain

Zinc finger, GAGA-binding factor (IPR015318)

Short name: Znf_GAGA-bd_fac

Overlapping homologous superfamilies

None.

Domain relationships

None.

Description

Zinc finger (Znf) domains are relatively small protein motifs which contain multiple finger-like protrusions that make tandem contacts with their target molecule. Some of these domains bind zinc, but many do not; instead binding other metals such as iron, or no metal at all. For example, some family members form salt bridges to stabilise the finger-like folds. They were first identified as a DNA-binding motif in transcription factor TFIIIA from Xenopus laevis (African clawed frog), however they are now recognised to bind DNA, RNA, protein and/or lipid substrates [PMID: 10529348, PMID: 15963892, PMID: 15718139, PMID: 17210253, PMID: 12665246]. Their binding properties depend on the amino acid sequence of the finger domains and of the linker between fingers, as well as on the higher-order structures and the number of fingers. Znf domains are often found in clusters, where fingers can have different binding specificities. There are many superfamilies of Znf motifs, varying in both sequence and structure. They display considerable versatility in binding modes, even between members of the same class (e.g. some bind DNA, others protein), suggesting that Znf motifs are stable scaffolds that have evolved specialised functions. For example, Znf-containing proteins function in gene transcription, translation, mRNA trafficking, cytoskeleton organisation, epithelial development, cell adhesion, protein folding, chromatin remodelling and zinc sensing, to name but a few [PMID: 11179890]. Zinc-binding motifs are stable structures, and they rarely undergo conformational changes upon binding their target.

Members of this entry bind to a 5'-GAGAG-3' DNA consensus binding site, and contain a Cys2-His2 zinc finger core as well as an N-terminal extension containing two highly basic regions. The zinc finger core binds in the DNA major groove and recognises the first three GAG bases of the consensus in a manner similar to that seen in other classical zinc finger-DNA complexes. The second basic region forms a helix that interacts in the major groove recognising the last G of the consensus, while the first basic region wraps around the DNA in the minor groove and recognises the A in the fourth position of the consensus sequence [PMID: 9033593].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
Pfam