Fig. 6.

The cytotoxic region of the CMS-associated gene orf288. (A) Truncated orf288 with different transmembrane domains: (a) full-length DNA sequence with three transmembrane domains; (b) truncated orf288 without the first transmembrane domain; (c) truncated orf288 without any transmembrane domains; (d) truncated orf288 that does not include 105-aa at the C-terminus; (e) truncated orf288 with only the third transmembrane domain; and (f) truncated orf288 with only part of the third transmembrane domain. (B) Effect of the overexpression of different truncated orf288 fragments on the growth of E. coli cells: (a–f) indicate the different truncated fragments shown in (A). IPTG was added when cell growth reached an OD₅₅₀ of 0.6. PET indicates the control expression vector induced by IPTG.