(a) Crude extracts from overnight (O.N.) cultures of non-induced and IPTG-induced E. coli harbouring the wild-type expression plasmid, and Ni-NTA affinity-purified wild-type AdoHcyase, (b) Ni-NTA affinity-purified thrombin-cleaved or uncleaved recombinant AdoHcyases (1 μg). M, molecular-mass standards (Roti-Mark Standard; Carl Roth, Karlsruhe, Germany), from top to bottom: β-galactosidase (119 kDa), serum albunium (66 kDa), ovalbumin (43 kDa) and carbonic anhydrase (29 kDa). +T, thrombin-cleaved protein.