The eutT gene of Salmonella enterica encodes an oxygen-labile, metal-containing ATP:Corrinoid adenosyltransferase enzyme
The eutT gene of Salmonella enterica encodes an oxygen-labile, metal-containing ATP:Corrinoid adenosyltransferase enzyme
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DOI：
10.1128/jb.186.17.5708-5714.2004
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发表时间：
2004-09-01
影响因子：
3.2
通讯作者：
Escalante-Semerena, JC
中科院分区：
文献类型：
--
作者：
Buan, NR;Suh, SJ;Escalante-Semerena, JC
本研究克隆并高效表达了沙门氏菌eutT基因，并对其产物进行了体内、外功能研究。EutT蛋白具有与之相关的氧不稳定的、含金属的ATP：co（I）rinoid腺苷转移酶活性。EutT和管家ATP：co（I）rinoid腺苷转移酶CobA酶之间的功能冗余通过突变菌株的表型分析来证明。缺乏CobA和EutT阻碍了乙醇胺的利用。EutT是S.肠球菌EutT菌株对乙醇胺作为碳源和能量源或氮源。反式提供的eutT（+）基因纠正了cobA菌株中eut-lacZ操纵子融合的腺苷钴胺素依赖性转录。富含EutT蛋白的细胞提取物含有强的、容易检测的ATP：co（I）rinoid腺苷转移酶活性。仅在缺氧条件下保持的提取物中检测到活性，暴露于空气或用Fe 21离子螯合剂红菲咯啉处理后活性完全丧失。虽然不能排除另一种金属离子的参与，但观察到的对空气和红菲咯啉的敏感性表明Fe 2+的参与。我们认为EutT蛋白是一种独特的含金属的ATP：co（I）rinoid腺苷转移酶。目前还不清楚金属离子是否起着结构或催化作用。
The eutT gene of Salmonella enterica was cloned and overexpressed, and the function of its product was established in vivo and in vitro. The EutT protein has an oxygen-labile, metal-containing ATP:co(I)rrinoid adenosyltransferase activity associated with it. Functional redundancy between EutT and the housekeeping ATP: co(I)rrinoid adenosyltransferase CobA enzyme was demonstrated through phenotypic analyses of mutant strains. Lack of CobA and EutT blocked ethanolamine utilization. EutT was necessary and sufficient for growth of an S. enterica cobA eutT strain on ethanolamine as a carbon and energy or nitrogen source. A eutT(+) gene provided in trans corrected the adenosylcobalamin-dependent transcription of a eut-lacZ operon fusion in a cobA strain. Cell extracts enriched for EutT protein contained strong, readily detectable ATP:co(I)rrinoid adenosyltransferase activity. The activity was only detected in extracts maintained under anoxic conditions, with complete loss of activity upon exposure to air or treatment with the Fe 21 ion chelator bathophenanthroline. While the involvement of another metal ion cannot be ruled out, the observed sensitivity to air and bathophenanthroline suggests involvement of Fe2+. We propose that the EutT protein is a unique metal-containing ATP:co(I)rrinoid adenosyltransferase. It is unclear whether the metal ion plays a structural or catalytic role.