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Physicochemical characterisation of KEIF€-the intrinsically disordered N-terminal region of magnesium transporter A

Jephthah, Stéphanie LU ; Månsson, Linda K. LU ; Belić, Domagoj LU ; Morth, Jens Preben and Skepö, Marie LU (2020) In Biomolecules 10(4).
Abstract

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... (More)

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.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Circular dichroism spectroscopy, Cryogenic transmission electron microscopy, Intrinsically disordered proteins, Magnesium transporter, Membrane proteins, Molecular-dynamics simulations, Protein-vesicle interactions, Secondary structure, Small-angle X-ray scattering
in
Biomolecules
volume
10
issue
4
article number
623
publisher
Multidisciplinary Digital Publishing Institute (MDPI)
external identifiers
  • pmid:32316569
  • scopus:85083872620
ISSN
2218-273X
DOI
10.3390/biom10040623
language
English
LU publication?
yes
id
22ef0541-d804-421e-9048-966632e114fc
date added to LUP
2020-05-20 14:10:08
date last changed
2020-05-21 03:00:04
@article{22ef0541-d804-421e-9048-966632e114fc,
  abstract     = {<p>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.</p>},
  author       = {Jephthah, Stéphanie and Månsson, Linda K. and Belić, Domagoj and Morth, Jens Preben and Skepö, Marie},
  issn         = {2218-273X},
  language     = {eng},
  number       = {4},
  publisher    = {Multidisciplinary Digital Publishing Institute (MDPI)},
  series       = {Biomolecules},
  title        = {Physicochemical characterisation of KEIF€-the intrinsically disordered N-terminal region of magnesium transporter A},
  url          = {http://dx.doi.org/10.3390/biom10040623},
  doi          = {10.3390/biom10040623},
  volume       = {10},
  year         = {2020},
}