Figure 5. Analysis of the ‘Candidatus Liberibacter solanacearum’ arginine biosynthesis pathway.

The typical prokaryotic arginine biosynthesis pathway. The NAGK family of enzymes (COG0548) catalyze the second step in arginine biosynthesis and are known as ArgB in many bacteria [106], [107], [108], [109]. In general, NAGKs come in two forms: hexameric arginine-sensitive enzymes and dimeric arginine-insensitive enzymes. The arginine-sensitive varieties of these enzymes typically function as a critical point of feedback inhibition for arginine biosynthesis [24], [110], [111].