Deprotonation by dehydration: the origin of ammonium sensing in the AmtB channel.

ABSTRACT: The AmtB channel passively allows the transport of NH4(+) across the membranes of bacteria via a "gas" NH3 intermediate and is related by homology (sequentially, structurally, and functionally) to many forms of Rh protein (both erythroid and nonerythroid) found in animals and humans. New structural information on this channel has inspired computational studies aimed at clarifying various aspects of NH4(+) recruitment and binding in the periplasm, as well as its deprotonation. However, precise mechanisms for these events are still unknown, and, so far, explanations for subsequent NH3 translocation and reprotonation at the cytoplasmic end of the channel have not been rigorously addressed. We employ molecular dynamics simulations and free energy methods on a full AmtB trimer system in membran

SUBMITTER: Bostick DL 

PROVIDER: S-EPMC1796661 | biostudies-literature | 2007 Feb

REPOSITORIES: biostudies-literature