In enzymology, a scyllo-inosamine-4-phosphate amidinotransferase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are L-arginine and 1-amino-1-deoxy-scyllo-inositol 4-phosphate, whereas its two products are L-ornithine and 1-guanidino-1-deoxy-scyllo-inositol 4-phosphate.
This enzyme belongs to the family of transferases that transfer one-carbon groups, specifically the amidinotransferases. The systematic name of this enzyme class is L-arginine:1-amino-1-deoxy-scyllo-inositol-4-phosphate amidinotransferase. Other names in common use include L-arginine:inosamine-P-amidinotransferase, inosamine-P amidinotransferase, L-arginine:inosamine phosphate amidinotransferase, and inosamine-phosphate amidinotransferase. This enzyme participates in streptomycin biosynthesis.
As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code .