(1) It appears that RhiA and RhiB are cytoplasmic, whereas RhiC is a periplasmic protein, since it has a typical N-terminal transit sequence and a rhiC-phoA protein fusion expresses alkaline phosphatase activity.
(2) Protein extracts from a rhiB mutant retained rhizoxin binding affinity, therefore this rhizoxin resistance mechanism should not be a tubulin mediated process.
(3) These mutants mapped to two loci, rhiA and rhiB, and all of those with high resistance mapped to rhiA.