FIG. 4.
A periplasmic form of ApbE complements the thiamine requirement of an apbE mutant. (A) Growth of strain DM271 (apbE) carrying pApbEperi (●) or pApbE12 that produces wild-type ApbE (■) in minimal glucose medium supplemented with 10 nM thiamine where indicated. (B) Immunoblot showing the cellular location of ApbE and ApbEperi expressed from pApbE12 and pApbEperi, respectively. Cellular fractions were isolated as described in Materials and Methods. Abbreviations: WC, whole-cell proteins; CYT, cytoplasmic proteins; PERI, periplasmic proteins; TM, total membrane proteins.