期刊
PROTEIN SCIENCE
卷 19, 期 8, 页码 1565-1576出版社
WILEY
DOI: 10.1002/pro.437
关键词
aminoglycoside resistance; crystal structure; GTP-dependent; ATP-dependent; mechanism
资金
- National Institutes of Health [RO1 AI057393]
- Department of Energy, Office of Biological and Environmental Research (BER),
- National Institutes of Health, National Center for Research Resources (NCRR)
- Biomedical Technology Program (BTP)
- National Institute of General Medical Sciences (NIGMS)
Acquired resistance to aminoglycoside antibiotics primarily results from deactivation by three families of aminoglycoside-modifying enzymes. Here, we report the kinetic mechanism and structure of the aminoglycoside phosphotransferase 2 ''-IVa (APH(2 '')-IVa), an enzyme responsible for resistance to aminoglycoside antibiotics in clinical enterococcal and staphylococcal isolates. The enzyme operates via a Bi-Bi sequential mechanism in which the two substrates (ATP or GTP and an aminoglycoside) bind in a random manner. The APH(2 '')-IVa enzyme phosphorylates various 4,6-disubstituted aminoglycoside antibiotics with catalytic efficiencies (k(cat)/K-m) of 1.5 x 10(3) to 1.2 x 10(6) (M-1 s(-1)). The enzyme uses both ATP and GTP as the phosphate source, an extremely rare occurrence in the phosphotransferase and protein kinase enzymes. Based on an analysis of the APH(2 '')-IVa structure, two overlapping binding templates specifically tuned for hydrogen bonding to either ATP or GTP have been identified and described. A detailed understanding of the structure and mechanism of the GTP-utilizing phosphotransferases is crucial for the development of either novel aminoglycosides or, more importantly, GTP-based enzyme inhibitors which would not be expected to interfere with crucial ATP-dependent enzymes.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据