S-adenosyl-L-methionine-dependent 2-deoxy-scyllo-inosamine dehydrogenase (EC 1.1.99.38) (Butirosin biosynthesis protein N) (Radical S-adenosylmethionine dehydrogenase BtrN) (RS dehydrogenase BtrN) (Radical SAM dehydrogenase BtrN)