Figure 5.
Spt16 polypeptide stabilities. Extracts of isogenic spt16Δ derivatives maintained by plasmid-borne spt16 mutant alleles, including several with NTD point mutations (4), were made from cells growing at 23°C (−) or incubated at 39°C for 1 h with the protein-synthesis inhibitor cycloheximide (+), resolved electrophoretically, and assessed by western analysis for Spt16 polypeptide. India ink staining (66) prior to anti-Spt16 antibody binding (data not shown) and the 40 kDa non-specific band verified equal loading. The resected polypeptides Spt16-Δ922, Spt16-Δ(6–435), and Spt16-Δ369 have higher mobilities than full-length Spt16.