FIG. 1.

The His₆-Rbl2p–β-tubulin complex formed in vivo is devoid of α-tubulin. LTY292 cells carrying a plasmid-borne gene specifying His₆-Rbl2p under control of the GAL promoter were grown for 2 h in medium containing raffinose (uninduced) or galactose (induced). The His₆-Rbl2p was separated from extracts by using Ni-NTA beads. The whole-cell extracts (W.C.E.) and bound proteins were analyzed by immunoblotting for β-tubulin, α-tubulin, and Rbl2p as shown. The bottom film was exposed six times longer than the top two. The presence of β-tubulin in the bound proteins required expression of His₆-Rbl2p, but no α-tubulin was detected in the bound proteins under either condition.