2NUU

Regulating the Escherichia coli ammonia channel: the crystal structure of the AmtB-GlnK complex

Summary for 2NUU

• Entry DOI: 10.2210/pdb2nuu/pdb
• Descriptor: Ammonia channel, Nitrogen regulatory protein P-II 2, ADENOSINE-5'-DIPHOSPHATE, ... (4 entities in total)
• Functional Keywords: membrane protein complex, nitrogen regulation, ammonia transport, transport protein-signaling protein complex, transport protein/signaling protein
• Biological source: Escherichia coli; More
• Cellular location: Cell inner membrane; Multi-pass membrane protein: P69681
• Total number of polymer chains: 12
• Total formula weight: 336606.55

Authors

Conroy, M.J.,Durand, A.,Lupo, D.,Li, X.-D.,Bullough, P.A.,Winkler, F.K.,Merrick, M. (deposition date: 2006-11-09, release date: 2006-11-21, Last modification date: 2023-10-25)

Primary citation

Conroy, M.J.,Durand, A.,Lupo, D.,Li, X.-D.,Bullough, P.A.,Winkler, F.K.,Merrick, M.
The crystal structure of the Escherichia coli AmtB-GlnK complex reveals how GlnK regulates the ammonia channel
Proc.Natl.Acad.Sci.Usa, 104:1213-1218, 2007

PubMed Abstract: Amt proteins are ubiquitous channels for the conduction of ammonia in archaea, eubacteria, fungi, and plants. In Escherichia coli, previous studies have indicated that binding of the PII signal transduction protein GlnK to the ammonia channel AmtB regulates the channel thereby controlling ammonium influx in response to the intracellular nitrogen status. Here, we describe the crystal structure of the complex between AmtB and GlnK at a resolution of 2.5 A. This structure of PII in a complex with one of its targets reveals physiologically relevant conformations of both AmtB and GlnK. GlnK interacts with AmtB almost exclusively via a long surface loop containing Y51 (T-loop), the tip of which inserts deeply into the cytoplasmic pore exit, blocking ammonia conduction. Y51 of GlnK is also buried in the pore exit, explaining why uridylylation of this residue prevents complex formation.

PubMed: 17220269
DOI: 10.1073/pnas.0610348104

Experimental method

X-RAY DIFFRACTION (2.5 Å)