Glucose uptake in Azotobacter vinelandii occurs through a GluP transporter that is under the control of the CbrA/CbrB and Hfq-Crc systems

• Published in: Scientific reports 2017-04, Vol.7 (1), p.858-15, Article 858
• Main Authors: Quiroz-Rocha, Elva, Moreno, Renata, Hernández-Ortíz, Armando, Fragoso-Jiménez, Juan Carlos, Muriel-Millán, Luis Felipe, Guzmán, Josefina, Espín, Guadalupe, Rojo, Fernando, Núñez, Cinthia
• Format: Article
• Language: English
• Subjects: 38/22; 38/39; 38/70; 38/71; 38/77; 38/90; 5' Untranslated Regions; 631/326/325/2482; 631/337/384/521; 82; 82/29; 82/80; 82/83; Acetic acid; Azotobacter vinelandii; Azotobacter vinelandii - genetics; Azotobacter vinelandii - metabolism; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Carbon sources; Catabolite Repression; Galactose; Glucose; Glucose - metabolism; Glucose transporter; Histidine; Histidine kinase; Histidine Kinase - genetics; Histidine Kinase - metabolism; Host Factor 1 Protein - genetics; Host Factor 1 Protein - metabolism; Humanities and Social Sciences; Kinases; Monosaccharide Transport Proteins - genetics; Monosaccharide Transport Proteins - metabolism; mRNA; multidisciplinary; Overexpression; Pseudomonadaceae; Pseudomonas; Pseudomonas - genetics; Pseudomonas - metabolism; Reporter gene; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-00980-5

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.