Figure 1.

A Tomato Ubc13-Like Protein, Fni3, Interacts with the Fen Protein.

(A) Fni3 interacts with Fen in a yeast two-hybrid assay. This was demonstrated by the activation of the lacZ reporter gene (blue patches). Photographs were taken 30 h after streaking onto plates containing X-Gal. Expression of Fni3 and Fni3^C89G mutant proteins was examined by anti-HA immunoblotting. The arrow denotes the band in which Fni3 and Fni3^C89G was detected.

(B) Fni3 interacts physically with Fen in a GST pull-down assay. Binding of GST-Fen to MBP-tagged fusion protein, MBP-Fni3, MBP-Fni3^C89G, and MBP-AvrPtoB_1-387, was examined by immunoblotting using anti-MBP monoclonal antibody. GST was used as a negative control. MBP-AvrPtoB_1-387 was used as a positive control. The Coomassie blue–stained gel in the bottom panel (labeled as input) indicates equal amount of MBP fusion proteins were used for binding GST-Fen and GST in the assay. The numbers on the right show the molecular mass of marker proteins in kilodaltons.