Diversity of bisubstrate binding modes of adenosine analogue-oligoarginine conjugates in protein kinase a and implications for protein substrate interactions.
Crystal structures of the catalytic subunit α of cAMP-dependent protein kinase (PKAc) with three adenosine analogue-oligoarginine conjugates (ARCs) are presented. The rationally designed ARCs include moieties that, in combination, target both the ATP- and the peptide-substrate-binding sites of PKAc, thereby taking advantage of high-affinity binding interactions offered by the ATP site while utilizing an additional mechanism for target specificity via binding to the peptide substrate site. The crystal structures demonstrate that, in accord with the previously reported bisubstrate character of ARCs, the inhibitors occupy both binding sites of PKAc. Further, they show new binding modes that may also apply to natural protein substrates of PKAc, which have not been revealed by previous crystallographic studies. The crystal structures described here contribute to the understanding of the substrate-binding patterns of PKAc and should also facilitate the design of inhibitors targeting PKAc and related protein kinases.
Pflug
Alexander
A
Norwegian Structural Biology Centre, Department of Chemistry, University of Tromsø, N-9037 Tromsø, Norway. Electronic address: alexander.pflug@uit.no.
Rogozina
Jevgenia
J
Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia. Electronic address: rogozina@ut.ee.
Lavogina
Darja
D
Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia. Electronic address: darjalav@ut.ee.
Enkvist
Erki
E
Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia. Electronic address: erki.enkvist@ut.ee.
Uri
Asko
A
Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia. Electronic address: asko.uri@ut.ee.
Engh
Richard Alan
RA
Norwegian Structural Biology Centre, Department of Chemistry, University of Tromsø, N-9037 Tromsø, Norway. Electronic address: Richard.Engh@uit.no.
Bossemeyer
Dirk
D
German Cancer Research Center, Group of Structural Biochemistry, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. Electronic address: d.bossemeyer@dkfz-heidelberg.de.
D000241:Adenosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism*; D001120:Arginine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D018360:Crystallography, X-Ray; D017868:Cyclic AMP-Dependent Protein Kinases / Q000737:chemistry* / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D015394:Molecular Structure; D017434:Protein Structure, Tertiary
D004791:Enzyme Inhibitors; D001120:Arginine; D017868:Cyclic AMP-Dependent Protein Kinases; D000241:Adenosine