6hm1

Structural and thermodynamic signatures of ligand binding to an enigmatic chitinase-D from Serratia proteamaculansStructural and thermodynamic signatures of ligand binding to an enigmatic chitinase-D from Serratia proteamaculans

Structural highlights 6hm1 is a 1 chain structure with sequence from Serratia proteamaculans 568. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.54Å Ligands: , Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function A8GFD6_SERP5 Publication Abstract from PubMed The Gram-negative bacteria Serratia marcescens and Serratia proteamaculans have efficient chitinolytic machineries that degrade chitin into N-acetylglucosamine (GlcNAc), which is used as a carbon and energy source. The enzymatic degradation of chitin in these bacteria occurs through the synergistic action of glycoside hydrolases (GHs) that have complementary activities; an endo-acting GH (ChiC) making random scissions on the polysaccharide chains and two exo-acting GHs mainly targeting single reducing (ChiA) and nonreducing (ChiB) chain ends. Both bacteria produce low amounts of a fourth GH18 (ChiD) with an unclear role in chitin degradation. Here, we have determined the thermodynamic signatures for binding of (GlcNAc)6 and the inhibitor allosamidin to SpChiD as well as the crystal structure of SpChiD in complex with allosamidin. The binding free energies for the two ligands are similar (Delta Gr degrees = -8.9 +/- 0.1 and -8.4 +/- 0.1 kcal/mol, respectively) with clear enthalpic penalties (Delta Hr degrees = 3.2 +/- 0.1 and 1.8 +/- 0.1 kcal/mol, respectively). Binding of (GlcNAc)6 is dominated by solvation entropy change (- TDelta Ssolv degrees = -17.4 +/- 0.4 kcal/mol) and the conformational entropy change dominates for allosamidin binding (- TDelta Sconf degrees = -9.0 +/- 0.2 kcal/mol). These signatures as well as the interactions with allosamidin are very similar to those of SmChiB suggesting that both enzymes are nonreducing end-specific. Structural and Thermodynamic Signatures of Ligand Binding to the Enigmatic Chitinase D of Serratia proteamaculans.,Madhuprakash J, Dalhus B, Vaaje-Kolstad G, Sakuda S, Podile AR, Eijsink VGH, Sorlie M J Phys Chem B. 2019 Mar 4. doi: 10.1021/acs.jpcb.8b11448. PMID:30789732 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Chitinase 3D structures

spinqualitylabelsall models 6hm1, resolution 1.54Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image