4bv6 | pdb_00004bv6
Refined crystal structure of the human Apoptosis inducing factor
Structural highlights
Disease[AIFM1_HUMAN] Defects in AIFM1 are the cause of combined oxidative phosphorylation deficiency type 6 (COXPD6) [MIM:300816]. It is a mitochondrial disease resulting in a neurodegenerative disorder characterized by psychomotor delay, hypotonia, areflexia, muscle weakness and wasting.[1] [2] Function[AIFM1_HUMAN] Probable oxidoreductase that has a dual role in controlling cellular life and death; during apoptosis, it is translocated from the mitochondria to the nucleus to function as a proapoptotic factor in a caspase-independent pathway, while in normal mitochondria, it functions as an antiapoptotic factor via its oxidoreductase activity. The soluble form (AIFsol) found in the nucleus induces 'parthanatos' i.e. caspase-independent fragmentation of chromosomal DNA. Interacts with EIF3G,and thereby inhibits the EIF3 machinery and protein synthesis, and activates casapse-7 to amplify apoptosis. Plays a critical role in caspase-independent, pyknotic cell death in hydrogen peroxide-exposed cells. Binds to DNA in a sequence-independent manner.[3] [4] [5] Publication Abstract from PubMedThe execution of apoptosis or programmed cell death comprises both caspase-dependent and caspase-independent processes. Apoptosis inducing factor (AIF) was identified as a major player in caspase-independent cell death. It induces chromatin condensation and initial DNA cleavage via an unknown molecular mechanism. Here we report the crystal structure of human AIF at 1.8 A resolution. The structure reveals the presence of a strong positive electrostatic potential at the AIF surface, although the calculated isoelectric point for the entire protein is neutral. We show that recombinant AIF interacts with DNA in a sequence-independent manner. In addition, in cells treated with an apoptotic stimulus, endogenous AIF becomes co-localized with DNA at an early stage of nuclear morphological changes. Structure-based mutagenesis shows that DNA-binding defective mutants of AIF fail to induce cell death while retaining nuclear translocation. The potential DNA-binding site identified from mutagenesis also coincides with computational docking of a DNA duplex. These observations suggest that AIF-induced nuclear apoptosis requires a direct interaction with DNA. DNA binding is required for the apoptogenic action of apoptosis inducing factor.,Ye H, Cande C, Stephanou NC, Jiang S, Gurbuxani S, Larochette N, Daugas E, Garrido C, Kroemer G, Wu H Nat Struct Biol. 2002 Sep;9(9):680-4. PMID:12198487[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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