Structural highlights
Function[AMTB_ECOLI] Involved in the uptake of ammonia. [GLNK_ECOLI] P-II indirectly controls the transcription of the glutamine synthetase gene (glnA). P-II prevents NR-II-catalyzed conversion of NR-I to NR-I-phosphate, the transcriptional activator of GlnA. When P-II is uridylylated to P-II-UMP, these events are reversed. When the ratio of Gln to 2-ketoglutarate decreases, P-II is uridylylated to P-II-UMP, which causes the deadenylation of glutamine synthetase by GlnE, so activating the enzyme (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedAmt 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. The crystal structure of the Escherichia coli AmtB-GlnK complex reveals how GlnK regulates the ammonia channel.,Conroy MJ, Durand A, Lupo D, Li XD, Bullough PA, Winkler FK, Merrick M Proc Natl Acad Sci U S A. 2007 Jan 23;104(4):1213-8. Epub 2007 Jan 12. PMID:17220269[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References | ||||||||||||||||||||
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