HypA/HypB Interaction and Hydrogenase Maturation Figure 1. AfHypA and AfHypB form 1:1 heterodimeric complex. (A) Cell lysate containing GST-tagged AfHypA were loaded on to glutathione resin with (lane 1) or without (lane 2) AfHypB. After extensive washing, GST-AfHypA and AfHypB were co-eluted with 20 mM glutathione (lane 1). In contrast, no co-elution was observed in the resin (lane 3) and the GST (lane 4) controls. (B) Purified AfHypB dimer preloaded with various ligands were subjected to SEC/LS analysis. Refractive index (continuous lines) and molecular weight (dotted lines) were plotted in the chromatogram. AfHypB preloaded with both GMPPNP and Ni (red) was eluted as a major peak with observed molecular weigh 51 kDa. AfHypB preloaded with GMPPNP (green) showed a broadened peak with observed molecular weight ,36 kDa. AfHypB preloaded with Ni (brown) showed two eluted peaks with PLoS ONE | www.plosone.org 3 February 2012 | Volume 7 | Issue 2 | e32592