P{UAS-Ser.F2I} is identical to P{UAS-Ser.EI} except that the XbaI restriction site, which replaced nucleotides encoding Tyr1248 and Arg1249 in P{UAS-Ser.EI} , has been reverted to wild type by replacing it with the corresponding region from the original Ser cDNA clone.
Amino acid replacement: F2I.