Nucleotide Exchange from the High-Affinity ATP-Binding Site in SecA Is the Rate-Limiting Step in the ATPase Cycle of the Soluble Enzyme and Occurs through a Specialized Conformational State†

Biochemistry ◽  
2004 ◽  
Vol 43 (23) ◽  
pp. 7307-7327 ◽  
Author(s):  
John J. Fak ◽  
Anna Itkin ◽  
Daita D. Ciobanu ◽  
Edward C. Lin ◽  
Xiang-Jin Song ◽  
...  
Keyword(s):  
Binding Site ◽  
Conformational State ◽  
Atp Binding ◽  
Soluble Enzyme ◽  
Nucleotide Exchange ◽  
Atp Binding Site ◽  
High Affinity ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Rate Limiting

Microenvironment of the High Affinity ATP-Binding Site of Na+/K+-ATPase Is Slightly Acidic

1999 ◽  
Vol 254 (1) ◽  
pp. 215-221 ◽  
Author(s):  
Holger Linnertz ◽  
Edvard Lanz ◽  
Martin Gregor ◽  
Roberto Antolovic ◽  
Rita Krumscheid ◽  
...  
Keyword(s):  
Binding Site ◽  
Atp Binding ◽  
Atp Binding Site ◽  
High Affinity

scholarly journals Identification of the Magnesium-binding Domain of the High-affinity ATP-binding Site of theBacillus subtilisandEscherichia coliSecA Protein

1995 ◽  
Vol 270 (32) ◽  
pp. 18975-18982 ◽  
Author(s):  
Jeroen P. W. van der Wolk ◽  
Michael Klose ◽  
Janny G. de Wit ◽  
Tanneke den Blaauwen ◽  
Roland Freudl ◽  
...  
Keyword(s):  
Binding Site ◽  
Binding Domain ◽  
Atp Binding ◽  
Atp Binding Site ◽  
High Affinity ◽  
Magnesium Binding

scholarly journals Effect of salinity on modulation by ATP, protein kinases and FXYD2 peptide of gill (Na+, K+)-ATPase activity in the swamp ghost crab Ucides cordatus (Brachyura, Ocypodidae)

2020 ◽  
Author(s):  
Francisco A. Leone ◽  
Malson N. Lucena ◽  
Leonardo M. Fabri ◽  
Daniela P. Garçon ◽  
Carlos F.L. Fontes ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Binding Site ◽  
Protein Kinases ◽  
Atp Binding ◽  
List Type ◽  
Inhibit Activity ◽  
Ucides Cordatus ◽  
Atp Binding Site ◽  
High Affinity ◽  
Endogenous Protein

ABSTRACTThe gill (Na+, K+)-ATPase is the main enzyme that underpins osmoregulatory ability in crustaceans that occupy biotopes like mangroves, characterized by salinity variation. We evaluated osmotic and ionic regulatory ability in the semi-terrestrial mangrove crab Ucides cordatus after 10-days acclimation to different salinities. We also analyzed modulation by exogenous FXYD2 peptide and by endogenous protein kinases A and C, and Ca2+- calmodulin-dependent kinase of (Na+, K+)-ATPase activity. Hemolymph osmolality was strongly hyper-/hypo-regulated in crabs acclimated at 2 to 35 ‰S. Cl- was well hyper-/hypo- regulated although Na+ much less so, becoming iso-natremic at high salinity. (Na+, K+)- ATPase activity was greatest in isosmotic crabs (26 ‰S), diminishing progressively from 18 and 8 ‰S (≈0.5 fold) to 2 ‰S (0.04-fold), and decreasing notably at 35 ‰S (0.07-fold). At low salinity, the (Na+, K+)-ATPase exhibited a low affinity ATP-binding site that showed Michaelis-Menten behavior. Above 18 ‰S, an additional, high affinity ATP-binding site, corresponding to 10-20% of total (Na+, K+)-ATPase activity appeared. Activity is stimulated by exogenous pig kidney FXYD2 peptide, while endogenous protein kinases A and C and Ca2+/calmodulin-dependent kinase all inhibit activity. This is the first demonstration of inhibitory phosphorylation of a crustacean (Na+, K+)-ATPase by Ca2+/calmodulin-dependent kinase. Curiously, hyper-osmoregulation in U. cordatus shows little dependence on gill (Na+, K+)-ATPase activity, suggesting a role for other ion transporters. These findings reveal that the salinity acclimation response in U. cordatus consists of a suite of osmoregulatory and enzymatic adjustments that maintain its osmotic homeostasis in a challenging, mangrove forest environment.Graphical abstractHighlightsGill (Na+, K+)-ATPase activity is greatest in isosmotic crabs, diminishing in lower and higher salinities.A high affinity ATP-binding site (10-20% of total activity) is exposed above 18 ‰S.Exogenous FXYD2 peptide stimulates activity; endogenous PKA, PKC and CaMK inhibit activity.First demonstration of inhibitory phosphorylation of crustacean (Na+, K+)-ATPase by CaMK.Hyper-osmoregulation shows little dependence on (Na+, K+)-ATPase activity.

The high affinity ATP binding site modulates the SecA-precursor interaction

FEBS Letters ◽  
2000 ◽  
Vol 486 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Frank van Voorst ◽  
Ingrid J Vereyken ◽  
Ben de Kruijff
Keyword(s):  
Binding Site ◽  
Atp Binding ◽  
Atp Binding Site ◽  
High Affinity

Mutants of protein kinase A that mimic the ATP-binding site of Aurora kinase

2011 ◽  
Vol 440 (1) ◽  
pp. 85-93 ◽  
Author(s):  
Alexander Pflug ◽  
Taianá Maia de Oliveira ◽  
Dirk Bossemeyer ◽  
Richard A. Engh
Keyword(s):  
Amino Acid ◽  
Protein Kinase ◽  
Binding Site ◽  
Protein Kinase A ◽  
Aurora Kinase ◽  
Atp Binding ◽  
Atp Binding Site ◽  
High Affinity ◽  
Specific Inhibitors ◽  
Kinase A

We describe in the present paper mutations of the catalytic subunit α of PKA (protein kinase A) that introduce amino acid side chains into the ATP-binding site and progressively transform the pocket to mimic that of Aurora protein kinases. The resultant PKA variants are enzymatically active and exhibit high affinity for ATP site inhibitors that are specific for Aurora kinases. These features make the Aurora-chimaeric PKA a valuable tool for structure-based drug discovery tasks. Analysis of crystal structures of the chimaera reveal the roles for individual amino acid residues in the binding of a variety of inhibitors, offering key insights into selectivity mechanisms. Furthermore, the high affinity for Aurora kinase-specific inhibitors, combined with the favourable crystallizability properties of PKA, allow rapid determination of inhibitor complex structures at an atomic resolution. We demonstrate the utility of the Aurora-chimaeric PKA by measuring binding kinetics for three Aurora kinase-specific inhibitors, and present the X-ray structures of the chimaeric enzyme in complex with VX-680 (MK-0457) and JNJ-7706621 [Aurora kinase/CDK (cyclin-dependent kinase) inhibitor].

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