Glucose uptake in Azotobacter vinelandii occurs through a GluP transporter that is under the control of the CbrA/CbrB and Hfq-Crc systems.
Glucose uptake in Azotobacter vinelandii occurs through a GluP transporter that is under the control of the CbrA/CbrB and Hfq-Crc systems.
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DOI：
10.1038/s41598-017-00980-5
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发表时间：
2017-04-12
影响因子：
4.6
通讯作者：
Núñez C
中科院分区：
文献类型：
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作者：
Quiroz-Rocha E;Moreno R;Hernández-Ortíz A;Fragoso-Jiménez JC;Muriel-Millán LF;Guzmán J;Espín G;Rojo F;Núñez C
棕色固氮菌（Azotobacter vinelandii）是假单胞菌科（Pseudomonadaceae）中严格好氧的固氮细菌，其表现出优先使用乙酸盐而不是葡萄糖作为碳源。在这项研究中，我们发现GluP（Avin 04150），注释为H+-偶联葡萄糖-半乳糖同向转运体，是A. vinelandii。这种蛋白质广泛分布于细菌和古细菌中，在假单胞菌中并不常见。我们发现gluP的表达受CbrA/CbrB和Crc/Hfq两个调控系统的分解代谢物阻遏控制，这两个系统在A. vinelandii和假单胞菌属。虽然组氨酸激酶CbrA是必不可少的葡萄糖利用，过度表达的Crc蛋白逮捕细胞生长时，葡萄糖是唯一的碳源。Crc和Hfq蛋白来自A. vinelandii和P. putida能与gluPmRNA前导区富含RNA A的Hfq结合基序形成稳定的复合物。此外，在恶臭假单胞菌中，富含gluPA的Hfq结合基序是功能性的，并促进lacZ报告基因的翻译抑制。gluP在假单胞菌属中没有广泛分布，但受CbrA/CbrB和Crc/Hfq系统的控制，这一事实证明了这些系统在调节假单胞菌科代谢中的相关性。
Azotobacter vinelandii, a strict aerobic, nitrogen fixing bacterium in the Pseudomonadaceae family, exhibits a preferential use of acetate over glucose as a carbon source. In this study, we show that GluP (Avin04150), annotated as an H+-coupled glucose-galactose symporter, is the glucose transporter in A. vinelandii. This protein, which is widely distributed in bacteria and archaea, is uncommon in Pseudomonas species. We found that expression of gluP was under catabolite repression control thorugh the CbrA/CbrB and Crc/Hfq regulatory systems, which were functionally conserved between A. vinelandii and Pseudomonas species. While the histidine kinase CbrA was essential for glucose utilization, over-expression of the Crc protein arrested cell growth when glucose was the sole carbon source. Crc and Hfq proteins from either A. vinelandii or P. putida could form a stable complex with an RNA A-rich Hfq-binding motif present in the leader region of gluP mRNA. Moreover, in P. putida, the gluP A-rich Hfq-binding motif was functional and promoted translational inhibition of a lacZ reporter gene. The fact that gluP is not widely distributed in the Pseudomonas genus but is under control of the CbrA/CbrB and Crc/Hfq systems demonstrates the relevance of these systems in regulating metabolism in the Pseudomonadaceae family.