crystal structures of two aminoglycoside kinases bound with a eukaryotic protein kinase inhibitor晶体结构的两个氨基糖苷类激酶绑定与真核蛋白激酶抑制剂.pdf

Crystal Structures of Two Aminoglycoside Kinases Bound with a Eukaryotic Protein Kinase Inhibitor Desiree H. Fong1,2., Bing Xiong3.¤a, Jiyoung Hwang1¤b, Albert M. Berghuis1,2,3* 1 Department of Biochemistry, McGill University, Montreal, Quebec, Canada, 2 Groupe de Recherche GRASP, McGill University, Montreal, Quebec, Canada, 3 Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada Abstract Antibiotic resistance is recognized as a growing healthcare problem. To address this issue, one strategy is to thwart the causal mechanism using an adjuvant in partner with the antibiotic. Aminoglycosides are a class of clinically important antibiotics used for the treatment of serious infections. Their usefulness has been compromised predominantly due to drug inactivation by aminoglycoside-modifying enzymes, such as aminoglycoside phosphotransferases or kinases. These kinases are structurally homologous to eukaryotic Ser/Thr and Tyr protein kinases and it has been shown that some can be inhibited by select protein kinase inhibitors. The aminoglycoside kinase, APH(39)-IIIa, can be inhibited by CKI-7, an ATP-competitive inhibitor for the casein kinase 1. We have determined that CKI-7 is also a moderate inhibitor for the atypical APH(9)-Ia. Here we present the crystal structures of CKI-7-bound APH(3 9)-IIIa and APH(9)-Ia, the first structures of a eukaryotic protein kinase inhibitor in complex with bacterial kinases. CKI-7 binds to the nucleotide-binding pocket of the enzymes and its binding alters the conformation of the nucleotide-binding loop, the segment homologous to the glycine-rich loop in eurkaryotic protein kinases. Comparison of these structures with the CKI-7-bound casein kinase 1 reveals features in the bi