Figure 1.

Expression, purification, and functional analysis of Toc34ΔTM252. The protein was expressed as described in Materials and Methods. (A) Total bacterial extract before (lane 1) and after (lane 2) induction of expression, and the fraction after completed purification (lanes 3 and 4) was subjected to SDS/PAGE followed by Coomassie blue staining (lanes 1–3) or immunodetection using αToc34 antibodies (lane 4). Numbers indicate the molecular mass standard in kDa. (B) A total of 25 μg of either outer envelope protein or 2.5 μg purified Toc34ΔTM252–6His was incubated with [α-³²P]GTP at 4°C in the presence (lanes 1, 3–5) or absence (lane 2) of 5 mM MgCl₂ and in the presence of 1 mM of either GTP (lane 3), GDP (lane 4), or ATP (lane 5).