U S Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783, USA.
Microbiology (Reading). 2010 Nov;156(Pt 11):3478-3491. doi: 10.1099/mic.0.037085-0. Epub 2010 Jul 23.
Transcriptional analysis was performed on Clostridium acetobutylicum with the goal of identifying sugar-specific mechanisms for the transcriptional regulation of transport and metabolism genes. DNA microarrays were used to determine transcript levels from total RNA isolated from cells grown on media containing eleven different carbohydrates, including two pentoses (xylose, arabinose), four hexoses (glucose, mannose, galactose, fructose), four disaccharides (sucrose, lactose, maltose, cellobiose) and one polysaccharide (starch). Sugar-specific induction of many transport and metabolism genes indicates that these processes are regulated at the transcriptional level and are subject to carbon catabolite repression. The results show that C. acetobutylicum utilizes symporters and ATP-binding cassette (ABC) transporters for the uptake of pentose sugars, while disaccharides and hexoses are primarily taken up by phosphotransferase system (PTS) transporters and a gluconate : H(+) (GntP) transporter. The transcription of some transporter genes was induced by specific sugars, while others were induced by a subset of the sugars tested. Sugar-specific transport roles are suggested, based on expression comparisons, for various transporters of the PTS, the ABC superfamily and members of the major facilitator superfamily (MFS), including the GntP symporter family and the glycoside-pentoside-hexuronide (GPH)-cation symporter family. Additionally, updates to the C. acetobutylicum genome annotation are proposed, including the identification of genes likely to encode proteins involved in the metabolism of arabinose and xylose via the pentose phosphate pathway.
对丙酮丁醇梭菌进行了转录分析，旨在确定糖特异性的转录调控机制，以调节运输和代谢基因的表达。使用 DNA 微阵列从在含有 11 种不同碳水化合物的培养基中生长的细胞中分离的总 RNA 中确定转录本水平，这些碳水化合物包括两种戊糖（木糖、阿拉伯糖）、四种己糖（葡萄糖、甘露糖、半乳糖、果糖）、四种二糖（蔗糖、乳糖、麦芽糖、纤维二糖）和一种多糖（淀粉）。许多运输和代谢基因的糖特异性诱导表明这些过程受到转录水平的调控，并受到碳分解代谢物阻遏的影响。结果表明，丙酮丁醇梭菌利用协同转运蛋白和 ATP 结合盒（ABC）转运蛋白摄取戊糖，而二糖和己糖主要通过磷酸转移酶系统（PTS）转运蛋白和葡萄糖酸盐：H+（GntP）转运蛋白摄取。一些转运蛋白基因的转录被特定的糖诱导，而其他基因则被测试的部分糖诱导。根据表达比较，推测 PTS、ABC 超家族和主要易化子超家族（MFS）的各种转运蛋白、GntP 协同转运蛋白家族和糖苷-戊糖苷-己糖苷（GPH）-阳离子协同转运蛋白家族具有特定的糖转运作用。此外，还提出了对丙酮丁醇梭菌基因组注释的更新，包括鉴定可能编码涉及通过戊糖磷酸途径代谢阿拉伯糖和木糖的基因。
