Figure 4
Time-resolved enzyme crystallography. (a) Diagram of flow cell with a yoke support based on Wyckoff et al. (1967) for time-resolved enzyme crystallography [Nieh (1997) based on Petsko (1985)]. (b) The coordinates and structure factors of the 2 h model are 1ypn and the reduced cofactor HMBS (1ah5) showing that the time-resolved 2 h structure cofactor (1ypn) is also in the active state. The time-resolved 2 h electron density, contoured at 3σ (shown in orange), is in the active site adjacent to and above the side chain of Asp84, which plays a pivotal role throughout the catalytic reaction cycle. Also superimposed is the oxidized cofactor HMBS (PDB code 1pda), which is an inactive form of the enzyme. This figure was made with Coot (Emsley & Cowtan, 2004). |