9S8K

Structure of glycogen phosphorylase - tetrameric form - in complex with HPr from Escherichia coli

Summary for 9S8K

• Entry DOI: 10.2210/pdb9s8k/pdb
• Related: 9S7V 9S86 9S8B
• EMDB information: 54663
• Descriptor: Glycogen phosphorylase, Phosphocarrier protein HPr, ... (4 entities in total)
• Functional Keywords: glycogen phosphorylase, transferase
• Biological source: Escherichia coli; More
• Total number of polymer chains: 8
• Total formula weight: 427012.51

Authors

Di Domenico, V.,Mastrella, L.,Alcaide-Jimenez, A.,Villegas-Ruiz, J.C.,D'Angelo, C.,Cifuente, J.O.,Connell, S.R.,Guerin, M.E. (deposition date: 2025-08-05, release date: 2026-04-08, Last modification date: 2026-05-13)

Primary citation

Di Domenico, V.,Franceus, J.,Mastrella, L.,De Beul, E.,Alcaide-Jimenez, A.,Paredes-Martinez, F.,Villegas-Ruiz, J.C.,Holden, E.,Rey, A.D.,D'Angelo, C.,Cifuente, J.O.,Struwe, W.B.,Biondi, R.M.,Marina, A.,Connell, S.R.,Benesch, J.L.P.,Casino, P.,Colleoni, C.,Desmet, T.,Guerin, M.E.
Structural basis for phosphorylation and allosteric regulation of bacterial glycogen phosphorylase by histidine phosphocarrier protein.
Nat Commun, 2026

PubMed Abstract: Protein phosphorylation is a universal regulatory mechanism, controlling virtually all aspects of bacterial physiology and pathogenesis, yet histidine phosphorylation remains among the least understood. The histidine phosphocarrier protein HPr not only drives bacterial glucose transmembrane uptake through the phosphotransferase system (PTS), but also controls key enzymes for central carbon metabolism, including glycogen phosphorylase (GP). Here we report cryoEM structures of multimeric Escherichia coli GP and their complexes with HPr. The EM maps reveal an unanticipated density at H806 of GP, consistent with histidine phosphorylation within a histidine-rich pocket at the N-terminal domain. Enzymatic assays reveal that HPr transfers a phosphoryl group to the N1 position of a histidine residue in GP. Through an integrative structural, mutational and functional approach, we uncover the molecular basis of HPr- GP selectivity and define the allosteric mechanism by which HPr regulates GP. We establish histidine phosphorylation as a mechanism of GP regulation, expanding the traditional paradigm of glycogen metabolism control in bacteria.

PubMed: 42045210
DOI: 10.1038/s41467-026-71729-w

Experimental method

ELECTRON MICROSCOPY (2.06 Å)