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Your search keyword '"Ha, Nam-Chul"' showing total 26 results
Start Over Author "Ha, Nam-Chul" Journal biochemical and biophysical research communications
26 results on '"Ha, Nam-Chul"'

25. Beta-strand-mediated dimeric formation of the Ig-like domains of human lamin A/C and B1.

Author

Ahn J, Lee J, Jeong S, Kang SM, Park BJ, and Ha NC

Subjects
Crystallography, X-Ray, Humans, Models, Molecular, Protein Stability, Immunoglobulin Domains, Lamin Type A chemistry, Lamin Type A metabolism, Lamin Type B chemistry, Lamin Type B metabolism, Protein Multimerization
Abstract

Lamins are nuclear intermediate filament proteins that play an essential role in maintaining the nuclear structure by forming a 3-D meshwork. Lamins consist of the N-terminal unstructured head, the coiled-coil rod domain, and the C-terminal tail, which is mostly unstructured except for the Ig-like domain. To date, the Ig-like domain has been characterized as a monomeric structure. Here, we determined the crystal structures of human lamin A/C, including the Ig-like domain and its N- and C-terminal flanking sequences. Interestingly, the structures showed a homodimer formed by beta-strand interactions between the N- and C-terminal flanking sequences. This interaction also provides a molecular implication for the creation of a 3-D meshwork between the 3.5-nm-thick filaments. Furthermore, we determined the crystal structure of the corresponding region of lamin B1. The structure showed a similar dimeric assembly, also formed by beta-strand interactions, albeit the intersubunit distance was much shorter. Since the Ig-like domain contains many genetic hotspots causing lamin-related diseases in lamin A/C, our findings will help understand the detailed assembly of lamins in a 3-D meshwork structure and lamin-related diseases at the molecular level., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Published
2021
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26. The tip region of the MacA alpha-hairpin is important for the binding to TolC to the Escherichia coli MacAB-TolC pump.

Author

Xu Y, Sim SH, Song S, Piao S, Kim HM, Jin XL, Lee K, and Ha NC

Subjects
ATP-Binding Cassette Transporters chemistry, ATP-Binding Cassette Transporters genetics, Amino Acid Sequence, Anti-Bacterial Agents pharmacology, Bacterial Outer Membrane Proteins chemistry, Bacterial Outer Membrane Proteins genetics, Conserved Sequence, Escherichia coli drug effects, Escherichia coli Proteins chemistry, Escherichia coli Proteins genetics, Membrane Transport Proteins chemistry, Membrane Transport Proteins genetics, Molecular Sequence Data, Protein Structure, Secondary, ATP-Binding Cassette Transporters metabolism, Bacterial Outer Membrane Proteins metabolism, Drug Resistance, Bacterial, Escherichia coli metabolism, Escherichia coli Proteins metabolism, Membrane Transport Proteins metabolism
Abstract

The tripartite efflux pump MacAB-TolC found in gram-negative bacteria is involved in resistance to antibiotics. We previously reported the funnel-like hexameric structure of the adaptor protein MacA to be physiologically relevant. In this study, we investigated the role of the tip region of its alpha-hairpin, which forms a cogwheel structure in the funnel-like shape of the MacA hexamer. Mutational and biochemical analyses revealed that the conserved residues located at the tip region of the alpha-hairpin of MacA play an essential role in the binding of TolC. Our findings offer a molecular basis for understanding the drug resistance of pathogenic bacteria., (2010 Elsevier Inc. All rights reserved.)

Published
2010
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