3D3M

The Crystal Structure of the C-terminal region of Death Associated Protein 5(DAP5)

Summary for 3D3M

• Entry DOI: 10.2210/pdb3d3m/pdb
• Descriptor: Eukaryotic translation initiation factor 4 gamma 2 (2 entities in total)
• Functional Keywords: heat repeat domain, structural genomics, psi, protein structure initiative, israel structural proteomics center, ispc, acetylation, initiation factor, phosphoprotein, protein biosynthesis, repressor, translation regulation, translation
• Biological source: Homo sapiens (man)
• Total number of polymer chains: 2
• Total formula weight: 39315.13

Authors

Dym, O.,Israel Structural Proteomics Center (ISPC) (deposition date: 2008-05-12, release date: 2008-10-14, Last modification date: 2024-02-21)

Primary citation

Liberman, N.,Dym, O.,Unger, T.,Albeck, S.,Peleg, Y.,Jacobovitch, Y.,Branzburg, A.,Eisenstein, M.,Marash, L.,Kimchi, A.
The crystal structure of the C-terminal DAP5/p97 domain sheds light on the molecular basis for its processing by caspase cleavage.
J.Mol.Biol., 383:539-548, 2008

PubMed Abstract: DAP5/p97 (death-associated protein 5) is a member of the eukaryotic translation initiation factor 4G family. It functions as a scaffold protein promoting cap-independent translation of proteins. During apoptosis, DAP5/p97 is cleaved by caspases at position 792, yielding an 86-kDa C-terminal truncated isoform (DAP5/p86) that promotes translation of several mRNAs mediated by an internal ribosome entry site. In this study, we report the crystal structure of the C-terminal region of DAP5/p97 extending between amino acids 730 and 897. This structure consists of four HEAT-Repeats and is homologous to the C-terminal domain of eIF4GI, eIF5, and eIF2Bepsilon. Unlike the other proteins, DAP5/p97 lacks electron density in the loop connecting alpha3 and alpha4, which harbors the caspase cleavage site. Moreover, we observe fewer interactions between these two helices. Thus, previous mapping of this site by mutation analysis is confirmed here by the resolved structure of the DAP5/p97 C-terminus. In addition, we identified the position of two conserved aromatic and acidic boxes in the structure of the DAP5/p97 C-terminus. The acidic residues in the two aromatic and acidic boxes form a continuous negatively charged patch, which is suggested to make specific interactions with other proteins such as eIF2beta. The caspase cleavage of DAP5/p97 removes the subdomain carrying acidic residues in the AA-box motif, which may result in exposure of a hydrophobic surface. These intriguing structural differences between the two DAP5 isoforms suggest that they have different interaction partners and, subsequently, different functions.

PubMed: 18722383
DOI: 10.1016/j.jmb.2008.08.013

Experimental method

X-RAY DIFFRACTION (1.9 Å)