https://repository.kopri.re.kr/handle/201206/5114 Wed, 25 Mar 2026 03:25:43 GMT 2026-03-25T03:25:43Z https://repository.kopri.re.kr/handle/201206/6394 Title: Crystallization and preliminary X-ray crystallographic studies of the ice-binding protein from the Arctic yeast Leucosporidium sp. AY30 Authors: Moon, Jin Ho; Park, Kyoung Sun; Ahn, In-Young; Park, Hyun; Kim, Hak Jun; Chi, Young Min; Park, Ae-Kyung Abstract: Freezing is dangerous to cellular organisms because it causes an increase in the concentration of ions and other solutes in the plasma, denatues biomolecules and ruptures cell membranes. Some cold-adapted organisms can sruvive at subzero temperatures by producing proteins that bind to and inhibit the growth of ice cystals. To better understand the structure and function of these proteins, the ice-binding protein form Leucosporidium sp. AY30 (LeIBP) was over-expressed, purified and crystallized. The native crystal belonged to space group P432121, with unit-cell parameters a=b=98.05, c=106.13A. Since LeIBP lacks any cysteine or methionine residues, two leucine residues were substituted by methionine residues. The selenomethionine-substituted mutant crystallized in the same space group as the native protein.o temperatures by producing proteins that bind to and inhibit the growth of ice cystals. To better understand the structure and function of these proteins, the ice-binding protein form Leucosporidium sp. AY30 (LeIBP) was over-expressed, purified and crystallized. The native crystal belonged to space group P432121, with unit-cell parameters a=b=98.05, c=106.13A. Since LeIBP lacks any cysteine or methionine residues, two leucine residues were substituted by methionine residues. The selenomethionine-substituted mutant crystallized in the same space group as the native protein. Sat, 01 Jan 2011 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/6394 2011-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/5833 Title: Crystallization and preliminary X-ray crystallographic analysis of the human Kindlin-2 PH domain Authors: HaJeung Park; Jun Yop An; Lee, Jun Hyuck; Soo Hyun Eom; Kim, Hak Jun Abstract: Kindlins contribute the correct assembly of integrin-containing focal adhesion sites through their direct interaction with the cytoplasmic tail of β-integrins. The FERM domain of kindlins has a unique subdomain organization: the F2 subdomain harbors a centrally located pleckstrin homology (PH) domain thought to be involved in the membrane targeting of kindlins. FERM domains are found in a number of cytoskeletal proteins that mediate the interaction between integrins and cytosolic proteins. In the present study, the PH domain of human kindlin-2 was subcloned, solubly expressed in Escherichia coli and crystallized using the hanging-drop vapor-diffusion method. A diffraction data set was collected at 2.8 ？resolution using a synchrotron X-ray radiation source at the BL- 4A of the Pohang Accelerator Laboratory (Pohang, Korea).domain harbors a centrally located pleckstrin homology (PH) domain thought to be involved in the membrane targeting of kindlins. FERM domains are found in a number of cytoskeletal proteins that mediate the interaction between integrins and cytosolic proteins. In the present study, the PH domain of human kindlin-2 was subcloned, solubly expressed in Escherichia coli and crystallized using the hanging-drop vapor-diffusion method. A diffraction data set was collected at 2.8 ？resolution using a synchrotron X-ray radiation source at the BL- 4A of the Pohang Accelerator Laboratory (Pohang, Korea). Sat, 01 Jan 2011 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/5833 2011-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/5703 Title: The structural flexibility of the shank1 PDZ domain is important for its binding to different ligands Authors: Soo Jeong Park; Soo Hyun Eom; HaJeung Park; Lee, Jun Hyuck; Kim, Hak Jun Abstract: The PDZ domain of the shank protein interacts with numerous cell membrane receptors and cytosolic proteins via the loosely defined binding motif X-(Ser/Thr)-X-Φ-COOH (Φ represents hydrophobic residues) at the carboxyl terminus of its target protein. This enables shank to serve as a membrane-associated scaffold for the assembly of signaling complexes. As the list of proteins that bind to the shank PDZ domain grows, it is not immediately clear what structural element(s) mediate this domain's target specificity or the plasticity required to bind its different targets. Here, we have determined the crystal structure of the shank1 PDZ in complex with the βPIX C-terminal pentapeptide (642-646, DETNL) at 2.3 ？resolution and modeled shank1 PDZ binding to selected pentapeptide ligands.Overall, our study provides a new level of understanding of the specificity and structural plasticity of the shank PDZ domain.target protein. This enables shank to serve as a membrane-associated scaffold for the assembly of signaling complexes. As the list of proteins that bind to the shank PDZ domain grows, it is not immediately clear what structural element(s) mediate this domain's target specificity or the plasticity required to bind its different targets. Here, we have determined the crystal structure of the shank1 PDZ in complex with the βPIX C-terminal pentapeptide (642-646, DETNL) at 2.3 ？resolution and modeled shank1 PDZ binding to selected pentapeptide ligands.Overall, our study provides a new level of understanding of the specificity and structural plasticity of the shank PDZ domain. Sat, 01 Jan 2011 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/5703 2011-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/6534 Title: Recent Advances in Structural Studies of Antifreeze Proteins Authors: Lee, Sung Gu; Kim, Hak Jun; Lee, Jun Hyuck Abstract: Antifreeze proteins (AFPs) have ice binding affinity, depress freezing temperature and inhibit ice recystallization which protect cellular membranes in polar organisms. Recent structural studies of antifreeze proteins have significantly expanded our understanding of the structure-function relationship and ice crystal growth inhibition. Although AFPs (Type I-IV AFP from fish, insect AFP and Plant AFP) have completely different fold and no sequence homology, they share a common feature of their surface area for ice binding property. The conserved ice-binding sites are relatively flat and hydrophobic. For example, Type I AFP has an amphipathic, single α-helix and has regularly spaced Thr-Ala residues which make direct interaction with oxygen atoms of ice crystals. Unlike Type I AFP, Type II and III AFP are compact globular proteins that contain a flat ice-binding patch on the surface. Type II and Type III AFP show a remarkable structural similarity with the sugar binding lectin protein and C-terminal domain of sialic acid synthase, respectively. Type IV is assumed to form a four-helix bundle which has sequence similarity with apolipoprotein. The results of our modeling suggest an ice-binding induced structural change of Type IV AFP. Insect AFP has β-helical structure with a regular array of Thr-X-Thr motif. Threonine residues of each Thr-X-Thr motif fit well into the ice crystal lattice expanded our understanding of the structure-function relationship and ice crystal growth inhibition. Although AFPs (Type I-IV AFP from fish, insect AFP and Plant AFP) have completely different fold and no sequence homology, they share a common feature of their surface area for ice binding property. The conserved ice-binding sites are relatively flat and hydrophobic. For example, Type I AFP has an amphipathic, single α-helix and has regularly spaced Thr-Ala residues which make direct interaction with oxygen atoms of ice crystals. Unlike Type Sat, 01 Jan 2011 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/6534 2011-01-01T00:00:00Z