Journal article
Physicochemical Characterisation of KEIF-The Intrinsically Disordered N-Terminal Region of Magnesium Transporter A
Magnesium transporter A (MgtA) is an active transporter responsible for importing magnesium ions into the cytoplasm of prokaryotic cells. This study focuses on the peptide corresponding to the intrinsically disordered N-terminal region of MgtA, referred to as KEIF. Primary-structure and bioinformatic analyses were performed, followed by studies of the undisturbed single chain using a combination of techniques including small-angle X-ray scattering, circular dichroism spectroscopy, and atomistic molecular-dynamics simulations.
Moreover, interactions with large unilamellar vesicles were investigated by using dynamic light scattering, laser Doppler velocimetry, cryogenic transmission electron microscopy, and circular dichroism spectroscopy. KEIF was confirmed to be intrinsically disordered in aqueous solution, although extended and containing little β -structure and possibly PPII structure.
An increase of helical content was observed in organic solvent, and a similar effect was also seen in aqueous solution containing anionic vesicles. Interactions of cationic KEIF with anionic vesicles led to the hypothesis that KEIF adsorbs to the vesicle surface through electrostatic and entropic driving forces.
Considering this, there is a possibility that the biological role of KEIF is to anchor MgtA in the cell membrane, although further investigation is needed to confirm this hypothesis.
Language: | English |
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Publisher: | MDPI |
Year: | 2020 |
Pages: | 623 |
ISSN: | 2218273x |
Types: | Journal article |
DOI: | 10.3390/biom10040623 |
ORCIDs: | Morth, Jens Preben , 0000-0003-4287-506X , 0000-0002-7954-7046 and 0000-0002-8639-9993 |
Circular dichroism spectroscopy Crygenic transmission electron microscopy Intrinsically disordered proteins Magnesium trnasporter Membran proteins Molecular-dynamics simulations Protein-vesicle interactions Secondary structure Small-angle X-ray scattering
Adenosine Triphosphatases Amino Acid Motifs Amino Acid Sequence Chemical Phenomena Circular Dichroism Escherichia coli Escherichia coli Proteins Intrinsically Disordered Proteins Lipids Membrane Transport Proteins MgtA protein, E coli Microbiology Molecular Dynamics Simulation Particle Size Probability Protein Structure, Secondary QR1-502 Scattering, Small Angle Unilamellar Liposomes X-Ray Diffraction circular dichroism spectroscopy cryogenic transmission electron microscopy intrinsically disordered proteins magnesium transporter membrane proteins molecular-dynamics simulations protein–vesicle interactions secondary structure secondary structure. small-angle X-ray scattering