Structure of apoptosis-linked protein ALG-2 : Insights into Ca2+-induced changes in penta-EF-hand proteins
(2001) In Structure 9(4). p.267-275- Abstract
Background: The Ca2+ binding apoptosis-linked gene-2 (ALG-2) protein acts as a proapoptotic factor in a variety of cell lines and is required either downstream or independently of caspases for apoptosis to occur. ALG-2 belongs to the penta-EF-hand (PEF) protein family and has two high-affinity and one low-affinity Ca2+ binding sites. Like other PEF proteins, its N terminus contains a Gly/Pro-rich segment. Ca2+ binding is required for the interaction with the target protein, ALG-2 interacting protein 1 (AIP1). Results: We present the 2.3 Å resolution crystal structure of Ca2+-loaded des1-20ALG-2 (aa 21-191), which was obtained by limited proteolysis of recombinant ALG-2 with elastase. The... (More)
Background: The Ca2+ binding apoptosis-linked gene-2 (ALG-2) protein acts as a proapoptotic factor in a variety of cell lines and is required either downstream or independently of caspases for apoptosis to occur. ALG-2 belongs to the penta-EF-hand (PEF) protein family and has two high-affinity and one low-affinity Ca2+ binding sites. Like other PEF proteins, its N terminus contains a Gly/Pro-rich segment. Ca2+ binding is required for the interaction with the target protein, ALG-2 interacting protein 1 (AIP1). Results: We present the 2.3 Å resolution crystal structure of Ca2+-loaded des1-20ALG-2 (aa 21-191), which was obtained by limited proteolysis of recombinant ALG-2 with elastase. The molecule contains eight α helices that fold into five EF-hands, and, similar to other members of this protein family, the molecule forms dimers. Ca2+ ions bind to EF1, EF3, and, surprisingly, to EF5. In the related proteins calpain and grancalcin, the EF5 does not bind Ca2+ and is thought to primarily facilitate dimerization. Most importantly, the conformation of des1-20ALG-2 is significantly different from that of calpain and grancalcin. This difference can be described as a rigid body rotation of EF1-2 relative to EF4-5 and the dimer interface, with a hinge within the EF3 loop. An electron density, which is interpreted as a hydrophobic Gly/Pro-rich decapeptide that is possibly derived from the cleaved N terminus, was found in a hydrophobic cleft between these two halves of the molecule. Conclusions: A different relative orientation of the N- and C-terminal halves of des1-20ALG-2 in the presence of Ca2+ and the peptide as compared to other Ca2+-loaded PEF proteins changes substantially the shape of the molecule, exposing a hydrophobic patch on the surface for peptide binding and a large cleft near the dimer interface. We postulate that the binding of a Gly/Pro-rich peptide in the presence of Ca2+ induces a conformational rearrangement in ALG-2, and that this mechanism is common to other PEF proteins.
(Less)
- author
- Jia, Jia ; Tarabykina, Svetlana ; Hansen, Christian LU ; Berchtold, Martin and Cygler, Miroslaw
- publishing date
- 2001-09-01
- type
- Contribution to journal
- publication status
- published
- keywords
- Calcium binding proteins, Calcium-induced changes, Penta EF-hand proteins
- in
- Structure
- volume
- 9
- issue
- 4
- pages
- 9 pages
- publisher
- Cell Press
- external identifiers
-
- scopus:0034892270
- pmid:11525164
- ISSN
- 0969-2126
- DOI
- 10.1016/S0969-2126(01)00585-8
- language
- English
- LU publication?
- no
- id
- bbf881f9-f780-408a-83c5-2dfc53614afb
- date added to LUP
- 2018-09-11 14:50:27
- date last changed
- 2024-04-01 10:13:13
@article{bbf881f9-f780-408a-83c5-2dfc53614afb, abstract = {{<p>Background: The Ca<sup>2+</sup> binding apoptosis-linked gene-2 (ALG-2) protein acts as a proapoptotic factor in a variety of cell lines and is required either downstream or independently of caspases for apoptosis to occur. ALG-2 belongs to the penta-EF-hand (PEF) protein family and has two high-affinity and one low-affinity Ca<sup>2+</sup> binding sites. Like other PEF proteins, its N terminus contains a Gly/Pro-rich segment. Ca<sup>2+</sup> binding is required for the interaction with the target protein, ALG-2 interacting protein 1 (AIP1). Results: We present the 2.3 Å resolution crystal structure of Ca<sup>2+</sup>-loaded des1-20ALG-2 (aa 21-191), which was obtained by limited proteolysis of recombinant ALG-2 with elastase. The molecule contains eight α helices that fold into five EF-hands, and, similar to other members of this protein family, the molecule forms dimers. Ca<sup>2+</sup> ions bind to EF1, EF3, and, surprisingly, to EF5. In the related proteins calpain and grancalcin, the EF5 does not bind Ca<sup>2+</sup> and is thought to primarily facilitate dimerization. Most importantly, the conformation of des1-20ALG-2 is significantly different from that of calpain and grancalcin. This difference can be described as a rigid body rotation of EF1-2 relative to EF4-5 and the dimer interface, with a hinge within the EF3 loop. An electron density, which is interpreted as a hydrophobic Gly/Pro-rich decapeptide that is possibly derived from the cleaved N terminus, was found in a hydrophobic cleft between these two halves of the molecule. Conclusions: A different relative orientation of the N- and C-terminal halves of des1-20ALG-2 in the presence of Ca<sup>2+</sup> and the peptide as compared to other Ca<sup>2+</sup>-loaded PEF proteins changes substantially the shape of the molecule, exposing a hydrophobic patch on the surface for peptide binding and a large cleft near the dimer interface. We postulate that the binding of a Gly/Pro-rich peptide in the presence of Ca<sup>2+</sup> induces a conformational rearrangement in ALG-2, and that this mechanism is common to other PEF proteins.</p>}}, author = {{Jia, Jia and Tarabykina, Svetlana and Hansen, Christian and Berchtold, Martin and Cygler, Miroslaw}}, issn = {{0969-2126}}, keywords = {{Calcium binding proteins; Calcium-induced changes; Penta EF-hand proteins}}, language = {{eng}}, month = {{09}}, number = {{4}}, pages = {{267--275}}, publisher = {{Cell Press}}, series = {{Structure}}, title = {{Structure of apoptosis-linked protein ALG-2 : Insights into Ca<sup>2+</sup>-induced changes in penta-EF-hand proteins}}, url = {{http://dx.doi.org/10.1016/S0969-2126(01)00585-8}}, doi = {{10.1016/S0969-2126(01)00585-8}}, volume = {{9}}, year = {{2001}}, }