Identification of a gene encoding a tetrathionate hydrolase in Acidithiobacillus ferrooxidans
Identification of a gene encoding a tetrathionate hydrolase in Acidithiobacillus ferrooxidans
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DOI：
10.1016/j.jbiotec.2007.08.030
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发表时间：
2007-10-15
影响因子：
4.1
通讯作者：
Sugio, Tsuyoshi
中科院分区：
文献类型：
--
作者：
Kanao, Tadayoshi;Kamimura, Kazuo;Sugio, Tsuyoshi
连四硫酸盐是异化硫氧化过程中最重要的中间产物之一，其本身可被某些硫氧化微生物用作唯一的能源。连四硫酸盐水解酶（4THase）在连四硫酸盐氧化中起着重要作用，并且当硫氧化细菌在连四硫酸盐上生长时，应催化氧化异化的初始步骤。4TH酶活性在连四硫酸盐培养的嗜酸氧化亚铁硫杆菌ATCC 23270细胞中检测到，但在铁培养的细胞中没有检测到。从连四硫酸盐生长的细胞中纯化具有相同50 kDa多肽的二聚体结构的4TH酶。4THase在pH 3.0时酶活最高，在酸性条件下稳定性较高。通过使用A的数据库的BLAST检索鉴定编码纯化的4 TH酶的N-末端氨基酸序列的开放阅读框（ORF）。ferrooxidans ATCC 23270基因组。该基因在大肠杆菌中的异源表达导致形成非活性形式的蛋白质的包涵体。针对重组蛋白的抗血清清楚地识别纯化的天然4THase，表明ORF编码4THase。(C)2007 Elsevier B. V.保留所有权利。
Tetrathionate is one of the most important intermediates in dissimilatory sulfur oxidation and can itself be utilized as a sole energy source by some sulfur-oxidizing microorganisms. Tetrathionate hydrolase (4THase) plays a significant role in tetrathionate oxidation and should catalyze the initial step in the oxidative dissimilation when sulfur-oxidizing bacteria are grown on tetrathionate. 4THase activity was detected in tetrathionate-grown Acidithiobacillus ferrooxidans ATCC 23270 cells but not in iron-grown cells. A 4THase having a dimeric structure of identical 50 kDa polypeptides was purified from tetrathionate-grown cells. The 4THase showed the maximum activity at pH 3.0 and high stability under acidic conditions. An open reading frame (ORF) encoding the N-terminal amino acid sequence of the purified 4THase was identified by a BLAST search using the database for the A. ferrooxidans ATCC 23270 genome. Heterologous expression of the gene in Escherichia coli resulted in the formation of inclusion bodies of the protein in an inactive form. Antisera against the recombinant protein clearly recognized the purified native 4THase, indicating that the ORF encoded the 4THase. (C) 2007 Elsevier B.V. All rights reserved.