Domain

Zinc finger, CHY-type (IPR008913)

Short name: Znf_CHY

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.

Pirh2 is an eukaryotic ubiquitin protein ligase, which has been shown to promote p53 degradation in mammals. Pirh2 physically interacts with p53 and promotes ubiquitination of p53 independently of MDM2. Like MDM2, Pirh2 is thought to participate in an autoregulatory feedback loop that controls p53 function. Pirh2 proteins contain three distinct zinc fingers, the CHY-type, the CTCHY-type which is C-terminal to the CHY-type zinc finger and a RING finger. The CHY-type zinc finger has no currently known function [PMID: 12654245].

As well as Pirh2, the CHY-type zinc finger is also found in the following proteins:

  • Yeast helper of Tim protein 13. Hot13 may have a role in the assembly and recycling of the small Tims, a complex of the mitochondrial intermembrane space that participates in the TIM22 import pathway for assembly of the inner membrane [PMID: 15294910]
  • Several plant hypothetical proteins that also contain haemerythrin cation binding domains
  • Several protozoan hypothetical proteins that also contain a Myb domain

The solution structure of this zinc finger has been solved and binds 3 zinc atoms as shown in the following schematic representation:

                      ++---------+-----+
                      ||         |     |
         CXHYxxxxxxxxxCCxxxxxCxxCHxxxxxHxxxxxxxxxxxCxxCxxxxxxxxxCxxC
         | |                 |  |                  |  |         |  |
         +-+-----------------+--+                  +--+---------+--+

'C': conserved cysteine involved in the binding of one zinc atom.
'H': conserved histidine involved in the binding of one zinc atom.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0008270 zinc ion binding

Cellular Component

No terms assigned in this category.

Contributing signatures

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