6YC7

Structure of adenylylated C. glutamicum GlnK

Summary for 6YC7

• Entry DOI: 10.2210/pdb6yc7/pdb
• Related: 6CY6
• Descriptor: PII protein, ADENINE ARABINOSE-5'-PHOSPHATE, ADENOSINE MONOPHOSPHATE, ... (5 entities in total)
• Functional Keywords: pii, corynebacteria, nitrogen regulation, post-translational modification, adenylylation, signaling protein
• Biological source: Corynebacterium glutamicum
• Total number of polymer chains: 6
• Total formula weight: 75388.16

Authors

Grau, F.C.,Muller, Y.A. (deposition date: 2020-03-18, release date: 2021-03-24, Last modification date: 2024-01-24)

Primary citation

Grau, F.C.,Burkovski, A.,Muller, Y.A.
Crystal structures of adenylylated and unadenylylated P II protein GlnK from Corynebacterium glutamicum.
Acta Crystallogr D Struct Biol, 77:325-335, 2021

PubMed Abstract: P proteins are ubiquitous signaling proteins that are involved in the regulation of the nitrogen/carbon balance in bacteria, archaea, and some plants and algae. Signal transduction via P proteins is modulated by effector molecules and post-translational modifications in the P T-loop. Whereas the binding of ADP, ATP and the concomitant binding of ATP and 2-oxoglutarate (2OG) engender two distinct conformations of the T-loop that either favor or disfavor the interaction with partner proteins, the structural consequences of post-translational modifications such as phosphorylation, uridylylation and adenylylation are far less well understood. In the present study, crystal structures of the P protein GlnK from Corynebacterium glutamicum have been determined, namely of adenylylated GlnK (adGlnK) and unmodified unadenylylated GlnK (unGlnK). AdGlnK has been proposed to act as an inducer of the transcription repressor AmtR, and the adenylylation of Tyr51 in GlnK has been proposed to be a prerequisite for this function. The structures of unGlnK and adGlnK allow the first atomic insights into the structural implications of the covalent attachment of an AMP moiety to the T-loop. The overall GlnK fold remains unaltered upon adenylylation, and T-loop adenylylation does not appear to interfere with the formation of the two major functionally important T-loop conformations, namely the extended T-loop in the canonical ADP-bound state and the compacted T-loop that is adopted upon the simultaneous binding of Mg-ATP and 2OG. Thus, the P-typical conformational switching mechanism appears to be preserved in GlnK from C. glutamicum, while at the same time the functional repertoire becomes expanded through the accommodation of a peculiar post-translational modification.

PubMed: 33645536
DOI: 10.1107/S2059798321000735

Experimental method

X-RAY DIFFRACTION (1.8 Å)