Electron and atomic force microscopy of the trimeric ammonium transporter AmtB.

ABSTRACT: 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.

SUBMITTER: Conroy MJ 

PROVIDER: S-EPMC1299191 | biostudies-literature | 2004 Dec

REPOSITORIES: biostudies-literature