4yrb

mouse TDH mutant R180K with NAD+ bound

spinqualitylabelsall models 4yrb, resolution 3.25Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4yrb is a 6 chain structure with sequence from Lk3 transgenic mice. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: NAD Related: 4yr9, 4yra Gene: Tdh (LK3 transgenic mice) Activity: L-threonine 3-dehydrogenase, with EC number 1.1.1.103 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed Mouse l-threonine dehydrogenase (mTDH), which belongs to the short-chain dehydrogenase/reductase (SDR) superfamily and mediates threonine catabolism, plays pivotal roles in both powerful biosynthesis and signaling in mouse stem cells and has a regulatory residue Arg180. Here we determined three crystal structures of mTDH: wild-type (WT) in the apo form; in complex with NAD(+) and a substrate analog, glycerol, or with only NAD(+); as well as the R180K variant with NAD(+). This is the first description of a structure for mammalian SDR-type TDH. Structural comparison revealed the structural basis for SDR-type TDH catalysis remains strictly conserved in bacteria and mammals. Kinetic enzyme assays, and isothermal titration calorimetry (ITC) measurements indicated the R180K mutation has little effect on NAD(+) binding affinity, whereas affects the substrate's affinity for the enzyme. The crystal structure of R180K with NAD(+), biochemical and spectroscopic studies suggested that the R180K mutant should bind NAD(+) in a similar way and have a similar folding to the WT. However, the R180K variant may have difficulty adopting the closed form due to reduced interaction of residue 180 with a loop which connects a key position for mTDH switching between the closed and open forms in mTDH catalysis, and thereby exhibited a significantly decreased kcat/Km value toward the substrate, l-Thr. In sum, our results suggest that activity of GalE-like TDH can be regulated by remote interaction, such as hydrogen bonding and hydrophobic interaction around the Arg180 of mTDH. Structural insights on mouse l-threonine dehydrogenase: A regulatory role of Arg180 in catalysis.,He C, Huang X, Liu Y, Li F, Yang Y, Tao H, Han C, Zhao C, Xiao Y, Shi Y J Struct Biol. 2015 Dec;192(3):510-8. doi: 10.1016/j.jsb.2015.10.014. Epub 2015, Oct 19. PMID:26492815 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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