1v0d

From Proteopedia

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Template:STRUCTURE 1v0d

CRYSTAL STRUCTURE OF CASPASE-ACTIVATED DNASE (CAD)

Overview

CAD/DFF40 is responsible for the degradation of chromosomal DNA into nucleosomal fragments and subsequent chromatin condensation during apoptosis. It exists as an inactive complex with its inhibitor ICAD/DFF45 in proliferating cells but becomes activated upon cleavage of ICAD/DFF45 into three domains by caspases in dying cells. The molecular mechanism underlying the control and activation of CAD/DFF40 was unknown. Here, the crystal structure of activated CAD/DFF40 reveals that it is a pair of molecular scissors with a deep active-site crevice that appears ideal for distinguishing internucleosomal DNA from nucleosomal DNA. Ensuing studies show that ICAD/DFF45 sequesters the nonfunctional CAD/DFF40 monomer and is also able to disassemble the functional CAD/DFF40 dimer. This capacity requires the involvement of the middle domain of ICAD/DFF45, which by itself cannot remain bound to CAD/DFF40 due to low binding affinity for the enzyme. Thus, the consequence of the caspase-cleavage of ICAD/DFF45 is a self-assembly of CAD/DFF40 into the active dimer.

About this Structure

1V0D is a Single protein structure of sequence from Mus musculus. The following page contains interesting information on the relation of 1V0D with [Caspases]. Full crystallographic information is available from OCA.

Reference

Structural mechanism for inactivation and activation of CAD/DFF40 in the apoptotic pathway., Woo EJ, Kim YG, Kim MS, Han WD, Shin S, Robinson H, Park SY, Oh BH, Mol Cell. 2004 May 21;14(4):531-9. PMID:15149602 Page seeded by OCA on Sat May 3 11:55:59 2008