Fig. 6: Atomic details for CT and PT domains.
From: CryoEM structural exploration of catalytically active enzyme pyruvate carboxylase
a Model of tetrameric LlPC and enlargement of CT and PT domains from one subunit. The PT domain is colored in cyan, and at the CT the TIM barrel in green, the funnel subdomain in yellow and the connecting loop in purple. The CT active site is located at the entrance of the TIM barrel and surrounded by the funnel domain. b Overlap of CTempty (gray), CTpyr (blue) and CToxa (green) models. The largest conformational changes are produced in the helix 827-840 (bottom left corner) and the loop 610-617 (top). Arg606 interacts with pyruvate/oxaloacetate. In CTempty it moves to the outside and establishes a new interaction with Asn609. c In the CTreact model biotin interacts with Ser870. The hydroxyl group of Thr867, the methyl group of pyruvate and the amide group of biotin interact and have an extra density between them produced by the carboxyl group. In the figure, this group is shown bound to pyruvate producing oxaloacetate.
