Summary for 4HJY
| Entry DOI | 10.2210/pdb4hjy/pdb |
| Related | 3T36 4HJV 4HJZ |
| Related PRD ID | PRD_900017 |
| Descriptor | Endo-type membrane-bound lytic murein transglycosylase A, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (4 entities in total) |
| Functional Keywords | goose lysozyme-like structure, lytic transglycosylase, lyase |
| Biological source | Escherichia coli |
| Cellular location | Cell outer membrane; Lipid-anchor (Probable): P0C960 |
| Total number of polymer chains | 2 |
| Total formula weight | 47275.09 |
| Authors | Fibriansah, G.,Gliubich, F.I.,Thunnissen, A.-M.W.H. (deposition date: 2012-10-14, release date: 2012-10-24, Last modification date: 2023-09-20) |
| Primary citation | Fibriansah, G.,Gliubich, F.I.,Thunnissen, A.M. On the Mechanism of Peptidoglycan Binding and Cleavage by the endo-Specific Lytic Transglycosylase MltE from Escherichia coli. Biochemistry, 51:9164-9177, 2012 Cited by PubMed Abstract: The lytic transglycosylase MltE from Escherichia coli is a periplasmic, outer membrane-attached enzyme that cleaves the β-1,4-glycosidic bonds between N-acetylmuramic acid and N-acetylglucosamine residues in the cell wall peptidoglycan, producing 1,6-anhydromuropeptides. Here we report three crystal structures of MltE: in a substrate-free state, in a binary complex with chitopentaose, and in a ternary complex with the glycopeptide inhibitor bulgecin A and the murodipeptide N-acetylglucosaminyl-N-acetylmuramyl-l-Ala-d-Glu. The substrate-bound structures allowed a detailed analysis of the saccharide-binding interactions in six subsites of the peptidoglycan-binding groove (subsites -4 to +2) and, combined with site-directed mutagenesis analysis, confirmed the role of Glu64 as catalytic acid/base. The structures permitted the precise modeling of a short glycan strand of eight saccharide residues, providing evidence for two additional subsites (+3 and +4) and revealing the productive conformational state of the substrate at subsites -1 and +1, where the glycosidic bond is cleaved. Full accessibility of the peptidoglycan-binding groove and preferential binding of an N-acetylmuramic acid residue in a (4)C(1) chair conformation at subsite +2 explain why MltE shows only endo- and no exo-specific activity toward glycan strands. The results further indicate that catalysis of glycosidic bond cleavage by MltE proceeds via distortion toward a sofa-like conformation of the N-acetylmuramic acid sugar ring at subsite -1 and by anchimeric assistance of the sugar's N-acetyl group, as shown previously for the lytic transglycosylases Slt70 and MltB. PubMed: 23075328DOI: 10.1021/bi300900t PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.4 Å) |
Structure validation
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