Na(+)/glutamine (asparagine) cotransport by Staphylococcus lugdunensis and Corynebacterium amycolatum

Staphylococcus lugdunensis and Corynebacterium amycolatum each have a Na(+)/glutamine cotransporter that displays an ordered reaction sequence at the extracellular surface, with sodium binding (K(m) of 6.5 mM) before glutamine (K(m) of 50 microM). Asparagine is low-affinity substrate (K(m) approximately 1 mM) for each system.