The entire add gene cluster showed 78% identity to dnd gene cluster from S. lividans. In order to facilitate the study of biological function of add gene cluster, E.

• 同源性比较揭示add基因簇的addA基因与固氮酶基因nifS高度同源，add与变铅青链霉菌dnd核苷酸的同一性为78%25。