5C1E
Crystal Structure of the Pectin Methylesterase from Aspergillus niger in Penultimately Deglycosylated Form (N-acetylglucosamine Stub at Asn84)
Summary for 5C1E
| Entry DOI | 10.2210/pdb5c1e/pdb |
| Related | 5C1C |
| Descriptor | Pectinesterase, 2-acetamido-2-deoxy-beta-D-glucopyranose, SULFATE ION, ... (7 entities in total) |
| Functional Keywords | parallel beta helix, pectin methylesterase, hydrolase |
| Biological source | Aspergillus niger (strain ATCC 1015 / CBS 113.46 / FGSC A1144 / LSHB Ac4 / NCTC 3858a / NRRL 328 / USDA 3528.7) |
| Cellular location | Secreted : G3YAL0 |
| Total number of polymer chains | 1 |
| Total formula weight | 33048.78 |
| Authors | Jameson, G.B.,Williams, M.A.K.,Loo, T.S.,Kent, L.M.,Melton, L.D.,Mercadante, D. (deposition date: 2015-06-13, release date: 2015-07-01, Last modification date: 2024-11-06) |
| Primary citation | Kent, L.M.,Loo, T.S.,Melton, L.D.,Mercadante, D.,Williams, M.A.,Jameson, G.B. Structure and Properties of a Non-processive, Salt-requiring, and Acidophilic Pectin Methylesterase from Aspergillus niger Provide Insights into the Key Determinants of Processivity Control. J.Biol.Chem., 291:1289-1306, 2016 Cited by PubMed Abstract: Many pectin methylesterases (PMEs) are expressed in plants to modify plant cell-wall pectins for various physiological roles. These pectins are also attacked by PMEs from phytopathogens and phytophagous insects. The de-methylesterification by PMEs of the O6-methyl ester groups of the homogalacturonan component of pectin, exposing galacturonic acids, can occur processively or non-processively, respectively, describing sequential versus single de-methylesterification events occurring before enzyme-substrate dissociation. The high resolution x-ray structures of a PME from Aspergillus niger in deglycosylated and Asn-linked N-acetylglucosamine-stub forms reveal a 10⅔-turn parallel β-helix (similar to but with less extensive loops than bacterial, plant, and insect PMEs). Capillary electrophoresis shows that this PME is non-processive, halophilic, and acidophilic. Molecular dynamics simulations and electrostatic potential calculations reveal very different behavior and properties compared with processive PMEs. Specifically, uncorrelated rotations are observed about the glycosidic bonds of a partially de-methyl-esterified decasaccharide model substrate, in sharp contrast to the correlated rotations of processive PMEs, and the substrate-binding groove is negatively not positively charged. PubMed: 26567911DOI: 10.1074/jbc.M115.673152 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.75 Å) |
Structure validation
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