7ldw

Zoogloea ramigera biosynthetic thiolase Q183Y/Y218E/delH221/S227K/G248T mutant

spinqualitylabelsall models 7ldw, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7ldw is a 4 chain structure with sequence from Zoogloea ramigera. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.5Å Ligands: COA, GOL, NH4, SCY, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function THIL_SHIZO Publication Abstract from PubMed Activation of enzymes by monovalent cations (M+) is a widespread phenomenon in biology. Despite this, there are few structure-based studies describing the underlying molecular details. Thiolases are a ubiquitous and highly conserved family of enzymes containing both K+-activated and K+-independent members. Guided by structures of naturally occurring K+-activated thiolases, we have used a structure-based approach to engineer K+-activation into a K+-independent thiolase. To our knowledge, this is the first demonstration of engineering K+-activation into an enzyme, showing the malleability of proteins to accommodate M+ ions as allosteric regulators. We show that a few protein structural features encode K+-activation in this class of enzyme. Specifically, two residues near the substrate-binding site are sufficient for K+-activation: A tyrosine residue is required to complete the K+ coordination sphere, and a glutamate residue provides a compensating charge for the bound K+ ion. Further to these, a distal residue is important for positioning a K+-coordinating water molecule that forms a direct hydrogen bond to the substrate. The stability of a cation-pi interaction between a positively charged residue and the substrate is determined by the conformation of the loop surrounding the substrate-binding site. Our results suggest that this cation-pi interaction effectively overrides K+-activation, and is, therefore, destabilised in K+-activated thiolases. Evolutionary conservation of these amino acids provides a promising signature sequence for predicting K+-activation in thiolases. Together, our structural, biochemical and bioinformatic work provide important mechanistic insights into how enzymes can be allosterically activated by M+ ions. Engineering potassium activation into biosynthetic thiolase.,Marshall AC, Bruning JB Biochem J. 2021 Aug 13;478(15):3047-3062. doi: 10.1042/BCJ20210455. PMID:34338286 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Thiolase 3D structures

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