Derkaoui Meriem, Antunes Ana, Nait Abdallah Jamila, Poncet Sandrine, Mazé Alain, Ma Pham Que Mai, Mokhtari Abdelhamid, Deghmane Ala-Eddine, Joyet Philippe, Taha Muhamed-Kheir, Deutscher Josef
Micalis Institute, INRA, AgroParisTech, Universitx00E9; Paris-Saclay, Jouy-en-Josas, France.
J Mol Microbiol Biotechnol. 2016;26(5):320-32. doi: 10.1159/000447093. Epub 2016 Jul 26.
We identified the genes encoding the proteins for the transport of glucose and maltose in Neisseria meningitidis strain 2C4-3. A mutant deleted for NMV_1892(glcP) no longer grew on glucose and deletion of NMV_0424(malY) prevented the utilization of maltose. We also purified and characterized glucokinase and α-phosphoglucomutase, which catalyze early catabolic steps of the two carbohydrates. N. meningitidis catabolizes the two carbohydrates either via the Entner-Doudoroff (ED) pathway or the pentose phosphate pathway, thereby forming glyceraldehyde-3-P and either pyruvate or fructose-6-P, respectively. We purified and characterized several key enzymes of the two pathways. The genes required for the transformation of glucose into gluconate-6-P and its further catabolism via the ED pathway are organized in two adjacent operons. N. meningitidis also contains genes encoding proteins which exhibit similarity to the gluconate transporter (NMV_2230) and gluconate kinase (NMV_2231) of Enterobacteriaceae and Firmicutes. However, gluconate might not be the real substrate of NMV_2230 because N. meningitidis was not able to grow on gluconate as the sole carbon source. Surprisingly, deletion of NMV_2230 stimulated growth in minimal medium in the presence and absence of glucose and drastically slowed the clearance of N. meningitidis cells from transgenic mice after intraperitoneal challenge.
我们鉴定了脑膜炎奈瑟菌2C4-3株中编码葡萄糖和麦芽糖转运蛋白的基因。缺失NMV_1892（glcP）的突变体不再能在葡萄糖上生长，而缺失NMV_0424（malY）则阻止了麦芽糖的利用。我们还纯化并表征了催化这两种碳水化合物早期分解代谢步骤的葡萄糖激酶和α-磷酸葡萄糖变位酶。脑膜炎奈瑟菌通过Entner-Doudoroff（ED）途径或磷酸戊糖途径分解这两种碳水化合物，从而分别形成3-磷酸甘油醛和丙酮酸或6-磷酸果糖。我们纯化并表征了这两条途径的几种关键酶。将葡萄糖转化为6-磷酸葡萄糖酸及其通过ED途径进一步分解代谢所需的基因被组织在两个相邻的操纵子中。脑膜炎奈瑟菌还含有编码与肠杆菌科和厚壁菌门的葡萄糖酸盐转运蛋白（NMV_2230）和葡萄糖酸盐激酶（NMV_2231）相似的蛋白质的基因。然而，葡萄糖酸盐可能不是NMV_2230的真正底物，因为脑膜炎奈瑟菌不能以葡萄糖酸盐作为唯一碳源生长。令人惊讶的是，缺失NMV_2230在有和没有葡萄糖的情况下均刺激了在基本培养基中的生长，并在腹腔注射后显著减缓了转基因小鼠中脑膜炎奈瑟菌细胞的清除。
