6F7U

Molecular Mechanism of ATP versus GTP Selectivity of Adenylate Kinase

Summary for 6F7U

• Entry DOI: 10.2210/pdb6f7u/pdb
• Descriptor: Adenylate kinase, PHOSPHOMETHYLPHOSPHONIC ACID GUANYLATE ESTER, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: adenylate kinase, atp selectivity, gtp inhibition, inhibitor complex, transferase
• Biological source: Escherichia coli K-12
• Cellular location: Cytoplasm : P69441
• Total number of polymer chains: 1
• Total formula weight: 24165.54

Authors

Rogne, P.,Rosselin, M.,Grundstrom, C.,Hedberg, C.,Wolf-Watz, M.,Sauer, U.H. (deposition date: 2017-12-12, release date: 2018-03-14, Last modification date: 2024-05-01)

Primary citation

Rogne, P.,Rosselin, M.,Grundstrom, C.,Hedberg, C.,Sauer, U.H.,Wolf-Watz, M.
Molecular mechanism of ATP versus GTP selectivity of adenylate kinase.
Proc. Natl. Acad. Sci. U.S.A., 115:3012-3017, 2018

PubMed Abstract: Enzymatic substrate selectivity is critical for the precise control of metabolic pathways. In cases where chemically related substrates are present inside cells, robust mechanisms of substrate selectivity are required. Here, we report the mechanism utilized for catalytic ATP versus GTP selectivity during adenylate kinase (Adk) -mediated phosphorylation of AMP. Using NMR spectroscopy we found that while Adk adopts a catalytically competent and closed structural state in complex with ATP, the enzyme is arrested in a catalytically inhibited and open state in complex with GTP. X-ray crystallography experiments revealed that the interaction interfaces supporting ATP and GTP recognition, in part, are mediated by coinciding residues. The mechanism provides an atomic view on how the cellular GTP pool is protected from Adk turnover, which is important because GTP has many specialized cellular functions. In further support of this mechanism, a structure-function analysis enabled by synthesis of ATP analogs suggests that a hydrogen bond between the adenine moiety and the backbone of the enzyme is vital for ATP selectivity. The importance of the hydrogen bond for substrate selectivity is likely general given the conservation of its location and orientation across the family of eukaryotic protein kinases.

PubMed: 29507216
DOI: 10.1073/pnas.1721508115

Experimental method

X-RAY DIFFRACTION (1.4 Å)