Abstract

Actinoplanes sp. SE50/110 is the industrially relevant producer of acarbose, which is used in the treatment of diabetes mellitus. Recent studies elucidated the expression dynamics in Actinoplanes sp. SE50/110 during growth. From these data, we obtained a large genomic region (ACSP50_3900 to ACSP50_3950) containing 51 genes, of which 39 are transcribed in the same manner. These co-regulated genes were found to be stronger transcribed on maltose compared with glucose as a carbon source. The transcriptional regulator MalT was identified as an activator of this maltose-regulated large genomic region (MRLGR). Since most of the genes are poorly annotated, the function of this region is farther unclear. However, comprehensive BLAST analyses indicate similarities to enzymes involved in amino acid metabolism. We determined a conserved binding motif of MalT overlapping the -35 promoter region of 17 transcription start sites inside the MRLGR. The corresponding sequence motif 5′-TCATCC-5nt-GGATGA-3′ displays high similarities to reported MalT binding sites in Escherichia coli and Klebsiella pneumoniae, in which MalT is the activator of mal genes. A malT deletion and an overexpression mutant were constructed. Differential transcriptome analyses revealed an activating effect of MalT on 40 of the 51 genes. Surprisingly, no gene of the maltose metabolism is affected. In contrast to many other bacteria, MalT is not the activator of mal genes in Actinoplanes sp. SE50/110. Finally, the MRLGR was found partly in other closely related bacteria of the family Micromonosporaceae. Even the conserved MalT binding site was found upstream of several genes inside of the corresponding regions.

Key points

• MalT is the maltose-dependent activator of a large genomic region in ACSP50_WT.

• The consensus binding motif is similar to MalT binding sites in other bacteria.

• MalT is not the regulator of genes involved in maltose metabolism in ACSP50_WT.

中文翻译：

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游动动动菌中麦芽糖调节的大基因组区域被转录调节因子 MalT 激活。 SE50/110

 抽象的

游动放线菌属sp. SE50/110是阿卡波糖的工业相关生产商，用于治疗糖尿病。最近的研究阐明了Actinoplanes sp 中的表达动态。生长期间的 SE50/110。从这些数据中，我们获得了包含 51 个基因的大基因组区域（ ACSP50_3900至ACSP50_3950 ），其中 39 个以相同方式转录。研究发现，与以葡萄糖为碳源的麦芽糖相比，这些共同调控的基因的转录能力更强。转录调节因子 MalT 被确定为麦芽糖调节大基因组区域 (MRLGR) 的激活剂。由于大多数基因的注释很差，该区域的功能还不清楚。然而，全面的 BLAST 分析表明与氨基酸代谢中涉及的酶有相似之处。我们确定了与 MRLGR 内 17 个转录起始位点的 -35 启动子区域重叠的 MalT 保守结合基序。相应的序列基序5'-TCATCC-5nt-GGATGA-3'与报道的大肠杆菌和肺炎克雷伯菌中的MalT结合位点表现出高度相似性，其中MalT是mal基因的激活剂。构建了malT缺失和过表达突变体。差异转录组分析揭示了 MalT 对 51 个基因中的 40 个有激活作用。令人惊讶的是，麦芽糖代谢的基因没有受到影响。与许多其他细菌相比，MalT 不是游动放线菌中mal基因的激活剂。 SE50/110。最后，在小单孢菌科其他密切相关的细菌中也发现了部分 MRLGR。 甚至在相应区域内的几个基因的上游也发现了保守的 MalT 结合位点。

 关键点

• MalT 是ACSP50_WT 中大基因组区域的麦芽糖依赖性激活剂。

•共有结合基序与其他细菌中的 MalT 结合位点相似。

• MalT 不是ACSP50_WT 中麦芽糖代谢相关基因的调节因子。