Involved in the biosynthesis of 3-amino-5-hydroxybenzoate (AHBA), a compound that then serves as the starter unit for the assembly of a polyketide during the biosynthesis of rifamycin B and other ansamycin antibiotics. Catalyzes only the phosphorylation of kanosamine to yield kanosamine 6-phosphate. ATP + kanosamine = ADP + D-kanosamine 6-phosphate + H(+) Inhibited by Zn(2+), Cu(2+), and Fe(2+). Antibiotic biosynthesis; rifamycin B biosynthesis. Belongs to the ROK (NagC/XylR) family.