• Title/Summary/Keyword: Structural biology

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Structural Analysis of the Ectodomain of HIV Gp41 and Implication on the Gp41 Assisted Membrane Fusion

  • Ryu, Jae-Ryen;Lee, Jung;Suh, Mu-Jin;Yu, Yeong-Sook;Yu, Yeon-Gyu
    • Proceedings of the Korean Biophysical Society Conference
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    • 1996.07a
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    • pp.33-33
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    • 1996
  • An ectodomain of gp41, the transmembrane fusion protein of HIV, without the fusion peptide region was expressed using pET system in E. coli. The expressed protein gp41core, was isolated as inclusion body and was purified by ion-exchange chromatography after solubilized in 6M urea. The purified denatured protein was renaturated and the folded domain of gp41core was identified by the presence of the proteolysis resistence domain and a high content of ${\alpha}$-helical secondary structure. (omitted)

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Structural Characterization for N-Terminal Domain of Caveolin-l

  • Kim, Jongmin;Shin, Jaeyoung;Park, Heonyong
    • Animal cells and systems
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    • v.7 no.3
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    • pp.207-211
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    • 2003
  • Caveolin-1 is a principal protein in the plasma membrane microdomains called caveolae. Caveolae play an important role in the transcytosis and pinocytosis. Therefore, caveolin-1 is most likely to work for the membrane dynamic events. In addition, caveolin-1 interacts with various signaling molecules. Although caveolin-1 possesses a variety of physiological functions, its structural properties were little construed. Here we analyzed the structural dynamics of the N-terminal caveolin-1 (residues 1-101), in order to better understand the structural properties in terms of its versatile functionality. We first analyzed its oligomeric form using GST-fused N-terminal domain, revealing that it equilibrates between a dimer and monomers in av concentration-dependent manner. The N-terminal domain of caveolin-1 was previously found to form a heptamer, so that our data suggest the dimeric form as an intermediate structure for the heptamer formation. Then, we obtained the folding profile, which indicated that $\DeltaG_{H2O}\;is\;about\;0.5\;\pm0.03$ kcal/mol. The stability of N-terminal domain is relatively low, indicating that N-terminal domain may not be crystalline. Conclusively, the dynamic and flexible structure of N-terminal domain appears more favorable to maintain the versatile functions of caveolin-1.

Random Sequence Analysis of the Genomic DNA of Methanopyrus kandleri and Molecular Cloning of the Gene Encoding a Homologue of the Catalytic Subunit of Carbon Monoxide Dehydrogenase

  • Shin, Hyun-Seock;Ryu, Jae-Ryeon;Han, Ye-Sun;Choi, Yong-Jin;Yu, Yeon-Gyu
    • Journal of Microbiology and Biotechnology
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    • v.9 no.4
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    • pp.404-413
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    • 1999
  • Methanopyrus kandleri is a hyperthermophilic methanogen that represents one of the most heat-resistant organisms: the maximum growth temperature of M. kandleri is $110^{\circ}C$. A random sequence analysis of the genomic DNA of M. kandleri has been performed to obtain genomic information. More than 200 unique sequence tags were obtained and compared with the sequences in the GenBank and PIR databases. About 30% of the analyzed tags showed strong sequence similarity to previously identified genes involved in various cellular processes such as biosynthesis, transport, methanogenesis, or metabolism. When statistics relating to the frequency of codons were examined, the sequenced open reading frames showed highly biased codon usage and a high content of charged amino acids. Among the identified genes, a homologue of the catalytic subunit of carbon monoxide dehydrogenase (CODH) that reduces $CO_2$ to CO was cloned and sequenced in order to examine its detailed gene structure. The cloned gene includes consensus promoters. The amino acid sequence of the cloned gene shows a strong homology with the CODH genes from methanogenic Archaea, especially in the presumed binding sites for Fe-S centers.

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Molecular Dynamics of the C-Terminal Domain Mouse CDT1 Protein

  • Khayrutdinov, Bulat I.;Bae, Won-Jin;Kim, Jeong-Ju;Hwang, Eun-Ha;Yun, Young-Mi;Ryu, Kyoung-Seok;Cheong, Hae-Kap;Kim, Yu-Gene;Cho, Yun-Je;Jeon, Young-Ho;Cheong, Chae-Joon
    • Journal of the Korean Magnetic Resonance Society
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    • v.11 no.1
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    • pp.30-41
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    • 2007
  • The backbone molecular dynamics of the C-terminal part of the mouse Cdt1 protein (tCdt1, residues 420-557) was studied by high field NMR spectroscopy. The Secondary structure of this protein was suggested by analyzing of chemical shift of backbone atoms with programs TALOS and PECAN, together with NOE connectivities from 3D $^{15}N-HSQC-NOESY$ data. Measurement of dynamic parameters $T_1,\;T_2$ and NOE and limited proteolysis experiment provided information for domain organization of tCdt1(420-557). Analysis of the experimental data showed that the C-terminal part of the tCdt1 has well folded domain for residues 455-553. The residues 420-453 including ${\alpha}-helix$ (432-441) are flexible and probably belong to other functional domain in intact full length Cdt1 protein.

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