Fig. 2. Mutations in the profilin-like motif of yeast B subunit reduce or eliminate actin-binding activity. (A) Alterations in the profilin-like motif made and analyzed in the current study. Amino acids 35–45 in wild-type Vma2p, Vma2p^Phe and Vma2p^Arch are compared. (B) Haine's plot of Vma2p^Phe-MBP binding to F-actin. (C) Vma2p^Arch-MBP does not bind F-actin: Lane 1, supernatant and lane 2 pellet of 4.0 µmol l^–1 F-actin and 1.0 µmol l^–1 Vma2p^Arch-MBP. Lanes 3 and 4 are the supernatant and pellet of 8.0 µmol l^–1 F-actin and 1.0 µmol l^–1 Vma2p^Arch-MBP supernatant.