Institut für Genomforschung und Systembiologie, Centrum für Biotechnologie, Universität Bielefeld, Universitätsstrasse 27, D-33615 Bielefeld, Germany.
J Biotechnol. 2009 Sep 25;143(4):239-46. doi: 10.1016/j.jbiotec.2009.08.005. Epub 2009 Aug 7.
Corynebacterium glutamicum is an industrially important producer of amino acids and an emerging model system for the Corynebacterineae. The glxR gene of C. glutamicum ATCC 13032 encodes a DNA binding transcription factor of the Crp-Fnr protein family. Available data indicated a prominent role of GlxR in the transcriptional regulatory network of C. glutamicum. We have used recently published whole-genome annotations of several corynebacteria to derive further evidence for GlxR-mediated transcriptional regulation from a comparative genomics approach. A bioinformatic strategy detected 22 genes belonging to a proposed GlxR core regulon in corynebacteria. Binding of purified GlxR protein to 40-mer oligonucleotides representing predicted GlxR binding sites in the upstream region of core genes from C. glutamicum ATCC 13032 was verified in vitro by electrophoretic mobility shift assays. Based on current data, a reliable genome-scale prediction of GlxR binding sites was performed, indicating that about 14% of the annotated C. glutamicum genes might be under direct transcriptional control by GlxR. Integration of GlxR-mediated regulatory interactions with the data stored in CoryneRegNet enabled the reconstruction of a refined transcriptional regulatory network model for C. glutamicum. This network model exhibited a hierarchical and modular structure and is characterized by the presence of master regulators in each functional module, with GlxR serving as the dominating regulatory hub.
谷氨酸棒杆菌是一种重要的工业生产氨基酸的微生物,也是研究棒杆菌科的新兴模式生物。谷氨酸棒杆菌 ATCC 13032 的 glxR 基因编码 Crp-Fnr 蛋白家族的 DNA 结合转录因子。现有数据表明,GlxR 在谷氨酸棒杆菌的转录调控网络中起重要作用。我们利用最近发表的几种棒杆菌的全基因组注释,从比较基因组学的角度进一步证实了 GlxR 介导的转录调控。生物信息学策略检测到 22 个基因属于拟议的 GlxR 核心调控子,这些基因在谷氨酸棒杆菌 ATCC 13032 的核心基因上游区域的预测 GlxR 结合位点的 40 -mer 寡核苷酸上有结合。通过电泳迁移率变动分析,在体外验证了纯化的 GlxR 蛋白与来自谷氨酸棒杆菌 ATCC 13032 的核心基因上游区域的预测 GlxR 结合位点的 40 -mer 寡核苷酸的结合。基于目前的数据,对 GlxR 结合位点进行了可靠的基因组规模预测,表明大约 14%的注释谷氨酸棒杆菌基因可能受到 GlxR 的直接转录调控。将 GlxR 介导的调控相互作用与 CoryneRegNet 中存储的数据整合,使我们能够重建谷氨酸棒杆菌的精细转录调控网络模型。该网络模型具有层次化和模块化结构,其特点是每个功能模块中都存在主调控因子,而 GlxR 则作为主导的调控中心。