Figure 4

Further deletions of GtrIV loop No. 6. a) The sequence of the 19 amino acids located in GtrIV loop No. 6, which were targeted for further deletion. The dashes in the sequences of GtrIV FD1, FD2, FD3 and FD4 indicate the amino acids that were deleted in each deletion set. Amino acid numbers corresponding to the start and end of the peptide sequence are given below their respective residue. b) LPS Western blots of GtrIV deletion constructs that were transformed into SFL1616 (Serotype Y). Deletion constructs FD1(SFL2331) and FD2 (SFL2332) were able to convert serotype Y to serotype 4a, thus indicating functionality. The absence of bands for FD3 and FD4 indicates loss of function for these deletion mutants. c) Western blots of GtrIV Loop No. 6 further deletion constructs. All the further deletion constructs were detected when the membrane extracts were probed with anti-alkaline phosphatase. This indicated that the deletion proteins (which are fused to PhoA/LacZ) are expressed.