Preparing your results

Our searching services are busy right now. Your search will reload in five seconds.

X
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

Analysis of activator-binding sites on the APC/C supports a cooperative substrate-binding mechanism.

Molecular cell | Apr 10, 2009

http://www.ncbi.nlm.nih.gov/pubmed/19362536

The anaphase-promoting complex or cyclosome (APC/C) is a ubiquitin ligase essential for the completion of mitosis in all eukaryotic cells. Substrates are recruited to the APC/C by activator proteins (Cdc20 or Cdh1), but it is not known where substrates are bound during catalysis. We explored this problem by analyzing mutations in the tetratricopeptide-repeat-containing APC/C subunits. We identified residues in Cdc23 and Cdc27 that are required for APC/C binding to Cdc20 and Cdh1 and for APC/C function in vivo. Mutation of these sites increased the rate of activator dissociation from the APC/C but did not affect reaction processivity, suggesting that the mutations have little effect on substrate dissociation from the active site. Further studies revealed that activator dissociation from the APC/C is inhibited by substrate, and that substrates are not bound solely to activator during catalysis but interact bivalently with an additional binding site on the APC/C core.

Pubmed ID: 19362536 RIS Download

Mesh terms: Amino Acid Motifs | Amino Acid Sequence | Anaphase-Promoting Complex-Cyclosome | Apc8 Subunit, Anaphase-Promoting Complex-Cyclosome | Binding Sites | Cdc20 Proteins | Cdh1 Proteins | Cell Cycle Proteins | Enzyme Activation | Models, Biological | Molecular Sequence Data | Mutation | Protein Binding | Saccharomyces cerevisiae | Saccharomyces cerevisiae Proteins | Sequence Analysis, Protein | Ubiquitin-Protein Ligase Complexes

Research resources used in this publication

None found

Research tools detected in this publication

None found

Data used in this publication

None found

Associated grants

  • Agency: NIGMS NIH HHS, Id: R01 GM053270
  • Agency: NIGMS NIH HHS, Id: R01 GM053270
  • Agency: NIGMS NIH HHS, Id: R01 GM053270-19

Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.