Properties of a Basic Amino Acid Permease in Neurospora crassa

SUMMARY: The system for transporting arginine into Neurospora conidia is described and shown to be consistent with the permease concept. The arginine system is shown to be separate from that which transports the aromatic and branched-chain neutral amino acids. Metabolic energy is necessary to achieve a concentration of arginine in the conidia higher than the external medium but not to maintain this concentration differential. A canavanine resistant mutant is shown to transport the basic amino acids at a reduced rate but the mutant transports other amino acids at the normal rate.