Electron and atomic force microscopy of the trimeric ammonium transporter AmtB.
Escherichia coli AmtB is an archetypal member of the ammonium transporter (Amt) family, a family of proteins that are conserved in all domains of life. Reconstitution of AmtB in the presence of lipids produced large, ordered two-dimensional crystals. From these, a 12 A resolution projection map was determined by cryoelectron microscopy, and high-resolution topographs were acquired using atomic force microscopy. Both techniques showed the trimeric structure of AmtB in which each monomer seems to have a pseudo-two-fold symmetry. This arrangement is likely to represent the in vivo structure. This work provides the first views of the structure of any member of the Amt family.
Conroy
Matthew J
MJ
Department of Molecular Biology and Biotechnology, Krebs Institute for Biomolecular Research, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK.
Jamieson
Stuart J
SJ
Blakey
Daniel
D
Kaufmann
Thomas
T
Engel
Andreas
A
Fotiadis
Dimitrios
D
Merrick
Mike
M
Bullough
Per A
PA
D027682:Cation Transport Proteins / Q000737:chemistry*; D020285:Cryoelectron Microscopy; D003460:Crystallization; D004926:Escherichia coli; D029968:Escherichia coli Proteins / Q000737:chemistry*; D018625:Microscopy, Atomic Force
C111096:AmtB protein, E coli; D027682:Cation Transport Proteins; D029968:Escherichia coli Proteins