Subcellular localization of HupL and HypB in microaerobic, free-living R. leguminosarum cells. SPF25(pALPF1) whole cells (C), crude extracts (S10), the soluble fraction (S100), and membranes (MB) were analyzed for the presence of HupL and HypB proteins by immunoblotting. Arrows, HupL unprocessed (U) and processed (P) forms.