FIG. 4.

Expression Rep-GFP fusion protein mutants from PVX vectors. (A) Rep coding sequences were fused in frame to the GFP coding sequence in PVX/GFP vectors. The N-terminal 51 amino acids of Rep and the mutated amino acids within this region are indicated for PVX/AC14-GFP (5), PVX/AC1m4-GFP (4), PVX/AC1(R₂A-R₅A-R₇A—K₁₁A)-GFP (3), PVX/AC1(K₂₄A)-GFP (2), and PVX/AC1(HLH₅₈AAA)-GFP (1). (B) Western blot analysis of PXV coat protein (CP) expression. Proteins were extracted either from mock-inoculated plants (mock) or from plants infected with PVX/AC1(HLH₅₈AAA)-GFP (lane 1), PVX/AC1(K₂₄A)-GFP (lane 2), PVX/AC1(R₂A-R₅A-R₇A—K₁₁A)-GFP (lane 3), PVX/AC1m4-GFP (lane 4), PVX/AC14-GFP (lane 5), and PVX/GFP. The blot was probed with an antiserum raised against PVX coat protein. The positions and sizes of protein markers and the coat protein are indicated. (C) Detection of the Rep mRNA by RT-PCR. The positions and sizes of DNA markers (bp) are indicated. (D) Western blot analysis of Rep-GFP fusion protein expression. The blot was probed with an antiserum raised against GFP. The positions and sizes of protein markers, free GFP, and Rep-GFP fusion protein (*) are indicated. The samples in each lane of panels C and D correspond to those described in panel B.