RRC ID 6451
Author Hsiao YY, Nakagawa A, Shi Z, Mitani S, Xue D, Yuan HS.
Title Crystal structure of CRN-4: implications for domain function in apoptotic DNA degradation.
Journal Mol Cell Biol
Abstract Cell death related nuclease 4 (CRN-4) is one of the apoptotic nucleases involved in DNA degradation in Caenorhabditis elegans. To understand how CRN-4 is involved in apoptotic DNA fragmentation, we analyzed CRN-4's biochemical properties, in vivo cell functions, and the crystal structures of CRN-4 in apo-form, Mn(2+)-bound active form, and Er(3+)-bound inactive form. CRN-4 is a dimeric nuclease with the optimal enzyme activity in cleaving double-stranded DNA in apoptotic salt conditions. Both mutational studies and the structures of the Mn(2+)-bound CRN-4 revealed the geometry of the functional nuclease active site in the N-terminal DEDDh domain. The C-terminal domain, termed the Zn-domain, contains basic surface residues ideal for nucleic acid recognition and is involved in DNA binding, as confirmed by deletion assays. Cell death analysis in C. elegans further demonstrated that both the nuclease active site and the Zn-domain are required for crn-4's function in apoptosis. Combining all of the data, we suggest a structural model where chromosomal DNA is bound at the Zn-domain and cleaved at the DEDDh nuclease domain in CRN-4 when the cell is undergoing apoptosis.
Volume 29(2)
Pages 448-57
Published 2009-1-1
DOI 10.1128/MCB.01006-08
PII MCB.01006-08
PMID 18981218
PMC PMC2612515
MeSH Amino Acid Motifs Animals Apoptosis / physiology* Caenorhabditis elegans / metabolism Caenorhabditis elegans Proteins / chemistry* Caenorhabditis elegans Proteins / metabolism Calcium / metabolism Catalytic Domain Crystallography, X-Ray DNA Fragmentation* DNA, Helminth / metabolism Dimerization Endodeoxyribonucleases / chemistry* Endodeoxyribonucleases / metabolism Endonucleases / chemistry* Endonucleases / metabolism Hydrogen-Ion Concentration Magnesium / metabolism Models, Molecular Protein Conformation Protein Structure, Tertiary Zinc / metabolism
IF 3.611
Times Cited 17
C.elegans tm1415