Gel filtration chromatography
A Superdex 200 10/300 GL column (GE Healthcare Life Sciences) was equilibrated with Rv2623 dialysis buffer (Text S1) and calibrated using the following molecular mass standards: aldolase (158 kDa), bovine serum albumin (67 kDa), ovalbumin (43 kDa), chymotrypsinogen A (25 kDa) as described in the Amersham Pharmacia technical notes (GE Healthcare Life Sciences). The flow rate was set to 0.15 ml/min and elution of the protein was monitored at 280 nm.