Fig. S1.

S. venezuelae encodes two dynamin-like proteins that are developmentally regulated. (A) TEM image showing the phenotype of the ΔwhiH mutant (SV8). WhiH-deficient cells deposit sporulation septa irregularly, leading to the formation of long spore-like compartments with more than one chromosome. Black arrowheads point to missing sporulation septa. (Scale bar: 500 nm.) (B) Expression profile of dynA and dynB in the WT (solid line) and the ΔwhiH (SV8) mutant (dashed line) over the entire Streptomyces life cycle. The gray box indicates the period of sporulation-specific cell division. (C) Sequence alignment of GTPase domains from selected dynamin family members. Highly conserved residues involved in GTP binding and hydrolysis are underlined in red. Protein sequences: Bs, Bacillus subtilis; Ec, Escherichia coli; Hs, Homo sapiens; Np, Nostoc punctiforme; and Sv, Streptomyces venezuelae. (D) Output from TMPred server predicting two transmembrane helices for DynB (gray box). The corresponding amino acid positions for the predicted transmembrane domains are shown in the schematic in Fig. 1B. (E) Survival of spores from WT, ΔwhiH (SV8), and ΔdynaB (LUV001) cells after heat stress (55 °C) over a time period of 60 min. The experiment was carried out in duplicate and results are shown as means ± SD.