FIG. 2.

UV cross-linking of [α-³²P]GTP to wild-type and mutant septins purified from yeast. Strains were grown to mid-log phase at 23°C as described for Fig. 1, and septin complexes were purified using anti-Cdc3p antibodies. Septins were incubated with 2 μM [α-³²P]GTP and 300 μM ATP, followed by cross-linking with UV light. (Upper panel) Silver-stained SDS-PAGE gel of 10% of the purified sample. (Lower panel) Autoradiography of the remaining sample to detect cross-linked GTP. Numbers represent the fractions of total [³²P]GTP in the indicated band.