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PDBsum entry 6ht9

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protein ligands metals Protein-protein interface(s) links
Hydrolase PDB id
6ht9

 

 

 

 

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Contents
Protein chains
202 a.a.
316 a.a.
297 a.a.
Ligands
NAG-NAG
GOL ×3
NAG ×3
Metals
_ZN ×2
Waters ×46
PDB id:
6ht9
Name: Hydrolase
Title: Mouse fetuin-b in complex with crayfish astacin
Structure: Astacin. Chain: a, c. Synonym: crayfish small molecule proteinase. Other_details: mature form spanning residues 50-251 plus a catalytic zinc ion.. Fetuin-b. Chain: b, d. Synonym: fetuin-like protein irl685. Engineered: yes
Source: Astacus astacus. Noble crayfish. Organism_taxid: 6715. Mus musculus. Mouse. Organism_taxid: 10090. Gene: fetub. Expressed in: trichoplusia ni. Expression_system_taxid: 7111.
Resolution:
3.10Å     R-factor:   0.217     R-free:   0.270
Authors: F.X.Gomis-Ruth,T.Goulas,T.Guevara,A.Cuppari
Key ref: A.Cuppari et al. (2019). Structure of mammalian plasma fetuin-B and its mechanism of selective metallopeptidase inhibition. IUCrJ, 6, 317-330. PubMed id: 30867929 DOI: 10.1107/S2052252519001568
Date:
03-Oct-18     Release date:   13-Mar-19    
PROCHECK
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 Headers
 References

Protein chains
P07584  (ASTA_ASTAS) -  Astacin from Astacus astacus
Seq:
Struc:
251 a.a.
202 a.a.
Protein chain
Q9QXC1  (FETUB_MOUSE) -  Fetuin-B from Mus musculus
Seq:
Struc:
388 a.a.
316 a.a.
Protein chain
Q9QXC1  (FETUB_MOUSE) -  Fetuin-B from Mus musculus
Seq:
Struc:
388 a.a.
297 a.a.
Key:    Secondary structure

 Enzyme reactions 
   Enzyme class: Chains A, C: E.C.3.4.24.21  - astacin.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: Hydrolysis of peptide bonds in substrates containing five or more amino acids, preferentially with Ala in P1', and Pro in P2'.
      Cofactor: Zn(2+)

 

 
DOI no: 10.1107/S2052252519001568 IUCrJ 6:317-330 (2019)
PubMed id: 30867929  
 
 
Structure of mammalian plasma fetuin-B and its mechanism of selective metallopeptidase inhibition.
A.Cuppari, H.Körschgen, D.Fahrenkamp, C.Schmitz, T.Guevara, K.Karmilin, M.Kuske, M.Olf, E.Dietzel, I.Yiallouros, D.de Sanctis, T.Goulas, R.Weiskirchen, W.Jahnen-Dechent, J.Floehr, W.Stoecker, L.Jovine, F.X.Gomis-Rüth.
 
  ABSTRACT  
 
Mammalian fetuin-A and fetuin-B are abundant serum proteins with pleiotropic functions. Fetuin-B is a highly selective and potent inhibitor of metallo-peptidases (MPs) of the astacin family, which includes ovastacin in mammals. By inhibiting ovastacin, fetuin-B is essential for female fertility. The crystal structure of fetuin-B was determined unbound and in complex with archetypal astacin, and it was found that the inhibitor has tandem cystatin-type modules (CY1 and CY2). They are connected by an exposed linker with a rigid, disulfide-linked 'CPDCP-trunk', and are followed by a C-terminal region (CTR) with little regular secondary structure. The CPDCP-trunk and a hairpin of CY2 form a bipartite wedge, which slots into the active-site cleft of the MP. These elements occupy the nonprimed and primed sides of the cleft, respectively, but spare the specificity pocket so that the inhibitor is not cleaved. The aspartate in the trunk blocks the catalytic zinc of astacin, while the CY2 hairpin binds through a QWVXGP motif. The CY1 module assists in structural integrity and the CTR is not involved in inhibition, as verified by in vitro studies using a cohort of mutants and variants. Overall, the inhibition conforms to a novel 'raised-elephant-trunk' mechanism for MPs, which is reminiscent of single-domain cystatins that target cysteine peptidases. Over 200 sequences from vertebrates have been annotated as fetuin-B, underpinning its ubiquity and physiological relevance; accordingly, sequences with conserved CPDCP- and QWVXGP-derived motifs have been found from mammals to cartilaginous fishes. Thus, the raised-elephant-trunk mechanism is likely to be generally valid for the inhibition of astacins by orthologs of fetuin-B.
 

 

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