Regulatory role of XynR (YagI) in catabolism of xylonate in Escherichia coli K-12
Regulatory role of XynR (YagI) in catabolism of xylonate in Escherichia coli K-12
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XynR (YagI) 在大肠杆菌 K-12 木糖酸分解代谢中的调节作用
DOI：
10.1093/femsle/fnx220
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发表时间：
2017
影响因子：
2.1
通讯作者：
Ishihama Akira
中科院分区：
文献类型：
--
作者：
Shimada Tomohiro;Momiyama Eri;Yamanaka Yuki;Watanabe Hiroki;Yamamoto Kaneyoshi;Ishihama Akira
Escherichia coliK-12的基因组包含10个隐蔽噬菌体，共占基因组序列的3.6%。在这些神秘噬菌体的200多个预测基因中，有14个假定的转录因子(TF)基因，但它们的调控功能尚不清楚。作为理解隐噬菌体编码因子调控功能的初步尝试，我们试图鉴定未知功能的CP4-6隐噬菌体编码的Yagi的调节功能。经过SELEX筛选，Yagi主要结合在双向转录单位间隔区的单个位点上，Yaga(编码另一个未知的Tf)和yagEF(分别编码2-酮-3-脱氧葡萄糖酸醛缩酶和脱水酶)在该前噬菌体区域内。YagEF酶参与木糖在木酸下游的分解代谢。然后我们指定Yagi为XynR(木酸分解代谢调节因子)，这是一种罕见的单靶向转录因子。与这一预测的调控功能一致，XynR的活性被认为是由木酸控制的。即使在你体内发现了XynR的低亲和力结合部位。ColiK-12基因组，它们都在开放阅读框内，这意味着XynR的调控网络仍然固定在CR4-6原噬菌体中，对寄主没有显著影响。ColiK-12。
The genome ofEscherichia coliK-12 contains ten cryptic phages, altogether constituting about 3.6% of the genome in sequence. Among more than 200 predicted genes in these cryptic phages, 14 putative transcription factor (TF) genes exist, but their regulatory functions remain unidentified. As an initial attempt to make a breakthrough for understanding the regulatory roles of cryptic phage-encoded TFs, we tried to identify the regulatory function of CP4-6 cryptic prophage-encoded YagI with unknown function. After SELEX screening, YagI was found to bind mainly at a single site within the spacer of bidirectional transcription units,yagA(encoding another uncharacterized TF) andyagEF(encoding 2-keto-3-deoxy gluconate aldolase, and dehydratase, respectively) within this prophage region. YagEF enzymes are involved in the catabolism of xylose downstream from xylonate. We then designated YagI as XynR (regulator of xylonate catabolism), one of the rare single-target TFs. In agreement with this predicted regulatory function, the activity of XynR was suggested to be controlled by xylonate. Even though low-affinity binding sites of XynR were identified in theE. coliK-12 genome, they all were inside open reading frames, implying that the regulation network of XynR is still fixed within the CR4-6 prophage without significant influence over the hostE. coliK-12.