PROSITE documentation PDOC51872
Zinc finger ZBR-type profile


The post-translational modification of proteins by the covalent attachment of ubiquitin (ubiquitylation) regulates various cellular processes of eukaryotes. The ubiquitylation reaction is catalyzed by a set of three enzymes: ubiquitin-activating enzyme, E1; ubiquitin-conjugating enzyme, E2; and ubiquitin ligase, E3. The anaphase-promoting complex or cyclosome (APC/C) is a multisubunit E3 ligase enzyme that regulates cell division by promoting timely ubiquitin-mediated proteolysis of key cell-cycle regulatory proteins. Emi1/Fbx5 (early mitotic inhibitor 1; gene symbol, FBX05) and Emi2/Erp1/Fbx43 (endogenous meiotic inhibitor 2 or Emi1-related protein 1; gene symbol, FBX043) constitute the Emi/Erp protein family of APC/C inhibitors against the APC/C function, which controls cell division progress. Emi1 and Emi2 share the F-box (see <PDOC50181>) and DB motifs, the zinc-binding region (ZBR) with the in-between-RING (IBR) topology and the C6HC-type zinc-binding motif, and the C-terminal region with a conserved 14-residue sequence ending in the RL residues, termed the RL tail [1,2,3].

The ZBR-type zinc finger is an autonomously folded domain with a central, twisted, four-stranded β-sheet and two zinc ions on opposite ends of the sheet (see <PDB:2M6N>). One zinc is chelated by the β1-β2 and β3-β4 loops and the other by the β2-β3 loop and a loop following β 4. The ZBR finger displays an In-Between-RING (IBR) domain topology [1,2,3].

The profile we developed covers the entire ZBR-type zinc finger.

Last update:

August 2018 / First entry.


Technical section

PROSITE method (with tools and information) covered by this documentation:

ZF_ZBR, PS51872; Zinc finger ZBR-type profile  (MATRIX)


1AuthorsShoji S. Muto Y. Ikeda M. He F. Tsuda K. Ohsawa N. Akasaka R. Terada T. Wakiyama M. Shirouzu M. Yokoyama S.
TitleThe zinc-binding region (ZBR) fragment of Emi2 can inhibit APC/C by targeting its association with the coactivator Cdc20 and UBE2C-mediated ubiquitylation.
SourceFEBS Open Bio 4:689-703(2014).
PubMed ID25161877

2AuthorsFrye J.J. Brown N.G. Petzold G. Watson E.R. Grace C.R.R. Nourse A. Jarvis M.A. Kriwacki R.W. Peters J.-M. Stark H. Schulman B.A.
TitleElectron microscopy structure of human APC/C(CDH1)-EMI1 reveals multimodal mechanism of E3 ligase shutdown.
SourceNat. Struct. Mol. Biol. 20:827-835(2013).
PubMed ID23708605

3AuthorsChang L. Zhang Z. Yang J. McLaughlin S.H. Barford D.
TitleAtomic structure of the APC/C and its mechanism of protein ubiquitination.
SourceNature 522:450-454(2015).
PubMed ID26083744

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