Mutations that confer resistance to 2-deoxyglucose reduce the specific activity of hexokinase from Myxococcus xanthus.
Mutations that confer resistance to 2-deoxyglucose reduce the specific activity of hexokinase from Myxococcus xanthus.
复制标题
赋予 2-脱氧葡萄糖抗性的突变会降低黄粘球菌己糖激酶的比活性。
DOI：
10.1128/jb.181.7.2225-2235.1999
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发表时间：
1999
影响因子：
3.2
通讯作者：
SaierJr,MH
中科院分区：
文献类型：
--
作者：
Youderian,P;Lawes,MC;Creighton,C;Cook,JC;SaierJr,MH
葡萄糖类似物2-脱氧葡萄糖（2dGlc）抑制黄色粘球菌的生长和多细胞发育。突变体M.黄曲霉对2dGlc有抗性，命名为六突变体，以低自发频率出现。大肠杆菌glk基因在M. xanthus hexmutants恢复了2dGlc的敏感性，这表明这些突变体是在可溶性己糖激酶功能丧失后产生的，所述可溶性己糖激酶功能使2dGlc磷酸化以形成毒性中间体2-脱氧葡萄糖-6-磷酸。酶活性测定黄原胶提取物显示出可溶性己糖激酶（ATP：d-己糖-6-磷酸转移酶; EC 2.7.1.1）活性，但没有磷酸转移酶系统活性。hex突变体具有较低水平的己糖激酶活性比野生型，和hex突变体所表现出的己糖激酶活性水平与2dGlc抑制其生长和孢子形成的能力呈负相关。2dGlc和N-乙酰葡糖胺都是M.体外实验表明，2dGlc对黄原胶激酶的抑制作用与葡萄糖和N-乙酰氨基葡萄糖在体内可拮抗2dGlc的毒性作用一致。
The glucose analog 2-deoxyglucose (2dGlc) inhibits the growth and multicellular development ofMyxococcus xanthus. Mutants ofM. xanthusresistant to 2dGlc, designatedhexmutants, arise at a low spontaneous frequency. Expression of theEscherichia coli glk(glucokinase) gene inM. xanthus hexmutants restores 2dGlc sensitivity, suggesting that these mutants arise upon the loss of a soluble hexokinase function that phosphorylates 2dGlc to form the toxic intermediate, 2-deoxyglucose-6-phosphate. Enzyme assays ofM. xanthusextracts reveal a soluble hexokinase (ATP:d-hexose-6-phosphotransferase; EC 2.7.1.1 ) activity but no phosphotransferase system activities. Thehexmutants have lower levels of hexokinase activities than the wild type, and the levels of hexokinase activity exhibited by thehexmutants are inversely correlated with the ability of 2dGlc to inhibit their growth and sporulation. Both 2dGlc andN-acetylglucosamine act as inhibitors of glucose turnover by theM. xanthushexokinase in vitro, consistent with the finding that glucose andN-acetylglucosamine can antagonize the toxic effects of 2dGlc in vivo.