Micromonospora　inyoensis　produces　sisomicin　(Sm),　an　aminoglycoside　antibiotic.　The　gene　cluster　of　sisomicin　biosynthesis　spanning　ca.　47　kb　consists　of　37　ORFs　encoding　various　proteins　for　sisomicin　biosynthesis,　regulation,　resistance　and　transport.　The　comparative　genetic　studies　on　the　biosynthetic　genes　of　sisomicin　and　gentamicin　(Gm)　reveal　a　similar　biosynthetic　route　and　provide　a　framework　for　the　future　biosynthetic　studies.