A stable water chain in the hydrophobic pore of the AmtB ammonium transporter
JournalArticle (Originalarbeit in einer wissenschaftlichen Zeitschrift)
ID 57885
Author(s) Lamoureux, Guillaume; Klein, Michael L; Bernèche, Simon
Author(s) at UniBasel Bernèche, Simon
Year 2007
Title A stable water chain in the hydrophobic pore of the AmtB ammonium transporter
Journal Biophysical journal
Volume 92
Number 9
Pages / Article-Number L82-4

The accessibility of water molecules to the pore of the AmtB ammonium transporter is studied using molecular dynamics simulations. Free energy calculations show that the so-called hydrophobic pore can stabilize a chain of water molecules in a well of a few kcal/mol, using a favorable electrostatic binding pocket as an anchoring point. Moreover, the structure of the water chain matches precisely the electronic density maxima observed in x-ray diffraction experiments. This result questions the general assumption that the AmtB pore only contains ammonia (NH(3)) molecules diffusing in a single file fashion. The probable presence of water molecules in the pore would influence the relative stability of NH(3) and NH(4)(+), and thus calls for a reassessment of the overall permeation mechanism in ammonium transporters.

Publisher Biophysical Society
ISSN/ISBN 0006-3495
edoc-URL http://edoc.unibas.ch/dok/A5249309
Full Text on edoc No
Digital Object Identifier DOI 10.1529/biophysj.106.102756
PubMed ID http://www.ncbi.nlm.nih.gov/pubmed/17351012
ISI-Number WOS:000245544100004
Document type (ISI) Journal Article

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