(A) Locations of all S. cerevisiae mutants tested are shown as space-filling spheres mapped on the T. terrestris structure, with backbone colored by conservation. Positions of mutations resulting in stronger temperature sensitive growth phenotypes are colored red (e.g., S. cerevisiae Q365/R368), positions with weaker phenotypes are colored orange (e.g., S. cerevisiae D297/K301/F305), and positions with no growth phenotype are colored blue; the position corresponding to the sec7-1 mutation (S402L) is colored magenta. (B) Using a plasmid-shuffling assay, CEN plasmids bearing GFP-tagged Sec7 or Sec7f with the indicated mutations expressed via their endogenous promoter were tested for their ability to rescue a genomic sec7 deletion in a sensitized arf1Δ/ARF2 strain (CFY863). Growth of serial 10-fold dilutions after 3 days at 37°C is shown, comparing the shuffled strains on 5-FOA to their parents growing in parallel on synthetic complete media (SC). Changes in the number or size of colonies indicates a growth defect.