Transport and Catabolism of Carbohydrates by Neisseria meningitidis

Abstract

We identified the genes encoding the proteins for the transport of glucose and maltose in <i>Neisseria meningitidis</i> strain 2C4-3. A mutant deleted for <i>NMV_1892</i><i>(glcP)</i> no longer grew on glucose and deletion of <i>NMV_0424</i><i>(malY)</i> prevented the utilization of maltose. We also purified and characterized glucokinase and α-phosphoglucomutase, which catalyze early catabolic steps of the two carbohydrates. <i>N. meningitidis</i> 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. <i>N. meningitidis</i> also contains genes encoding proteins which exhibit similarity to the gluconate transporter <i>(NMV_2230)</i> and gluconate kinase <i>(NMV_2231)</i> of Enterobacteriaceae and Firmicutes. However, gluconate might not be the real substrate of <i>NMV_2230</i> because <i>N. meningitidi</i>s was not able to grow on gluconate as the sole carbon source. Surprisingly, deletion of <i>NMV_2230</i> stimulated growth in minimal medium in the presence and absence of glucose and drastically slowed the clearance of <i>N. meningitidis</i> cells from transgenic mice after intraperitoneal challenge.