8CAD

Cryo-EM structure of the Ceres homohexamer from Galleria mellonella saliva

Summary for 8CAD

• Entry DOI: 10.2210/pdb8cad/pdb
• Related: 8CA9 8CAN
• EMDB information: 16521 16524 16531
• Descriptor: acidic juvenile hormone-suppressible protein 1, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-6)]alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (5 entities in total)
• Functional Keywords: galleria mellonella, wax worm saliva, plastic degradation, polyethylene degradation, peases, hexamerin, hemocyanin/phenoloxidase superfamily, metal binding, unknown function
• Biological source: Galleria mellonella (greater wax moth)
• Total number of polymer chains: 6
• Total formula weight: 502710.16

Authors

Spinola-Amilibia, M.,Arias-Palomo, E. (deposition date: 2023-01-24, release date: 2023-10-04, Last modification date: 2024-11-20)

Primary citation

Spinola-Amilibia, M.,Illanes-Vicioso, R.,Ruiz-L Formula See Text Pez, E.,Colomer-Vidal, P.,Rodriguez, F.V.,Peces Perez, R.,Arias, C.F.,Torroba, T.,Sol Formula See Text, M.,Arias-Palomo, E.,Bertocchini, F.
Plastic degradation by insect hexamerins: Near-atomic resolution structures of the polyethylene-degrading proteins from the wax worm saliva.
Sci Adv, 9:eadi6813-eadi6813, 2023

PubMed Abstract: Plastic waste management is a pressing ecological, social, and economic challenge. The saliva of the lepidopteran larvae is capable of oxidizing and depolymerizing polyethylene in hours at room temperature. Here, we analyze by cryo-electron microscopy (cryo-EM) 's saliva directly from the native source. The three-dimensional reconstructions reveal that the buccal secretion is mainly composed of four hexamerins belonging to the hemocyanin/phenoloxidase family, renamed Demetra, Cibeles, Ceres, and a previously unidentified factor termed Cora. Functional assays show that this factor, as its counterparts Demetra and Ceres, is also able to oxidize and degrade polyethylene. The cryo-EM data and the x-ray analysis from purified fractions show that they self-assemble primarily into three macromolecular complexes with striking structural differences that likely modulate their activity. Overall, these results establish the ground to further explore the hexamerins' functionalities, their role in vivo, and their eventual biotechnological application.

PubMed: 37729416
DOI: 10.1126/sciadv.adi6813

Experimental method

ELECTRON MICROSCOPY (2.85 Å)