Sandbox Reserved 711: Difference between revisions
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The endo-polygalacturonase II (Polygalacturonase EC 3.2.1.15) of the fungus ''Aspergillus Niger'' is an enzyme which is involved in the rotting process. It specifically degrade polygalacturonate, a major carbohydrate constituent of plant cell wall pectin, by hydrolysis of the glycosidic bonds that link galacturonic acid residues. | The endo-polygalacturonase II (Polygalacturonase EC 3.2.1.15) of the fungus ''Aspergillus Niger'' is an enzyme which is involved in the rotting process. It specifically degrade polygalacturonate, a major carbohydrate constituent of plant cell wall pectin, by hydrolysis of the glycosidic bonds that link galacturonic acid residues. | ||
Polygalacturonase belongs to the Glycoside hydrolysases 28 (GH28) according to the sequence-based classification of glycoside hydrolysases. The enzyme of the GH28 family achieves the hydrolysis with an inverting molecular mechanism. | Polygalacturonase belongs to the Glycoside hydrolysases 28 (GH28) according to the sequence-based classification of glycoside hydrolysases. The enzyme of the GH28 family achieves the hydrolysis with an inverting molecular mechanism.<ref>http://www.cazypedia.org/index.php/Inverting#Mechanistic_classification</ref> | ||
== Glycoside hydrolases and pectinases == | == Glycoside hydrolases and pectinases == | ||
The endopolygalacturonase II belongs to the family of | |||
The endopolygalacturonase II belongs to the family of glycoside hydrolases, enzymes that hydrolyse glycosidic bonds in polysaccharidic chains and release smaller sugars, classified in the EC 3.2.1.x group. Within this family, endopolygalacturonases are pectinases, enzymes involved in the degradation of pectin, a polymer of galacturonic acid and rhamnose that is the jelly-like component of plant cell walls. | |||
Endopolygalacturonase II is part of the family 28 of glycoside hydrolases. It is not the only endopolygalacturonase from A. niger - a family of seven genes encode such enzymes, and six different proteins have been identified: endopolygalacturonases I, II, A, B, C and E. | Endopolygalacturonase II is part of the family 28 of glycoside hydrolases. It is not the only endopolygalacturonase from A. niger - a family of seven genes encode such enzymes, and six different proteins have been identified: endopolygalacturonases I, II, A, B, C and E. | ||
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== Description of the structure == | == Description of the structure == | ||
{{STRUCTURE_1czf| PDB=1czf | SCENE= }} | |||
The endopolygalacturonase II from Aspergillus niger has a beta-helix structure<ref>http://www.ncbi.nlm.nih.gov/pubmed/10521427</ref>: the chain folds into 10 turns, shaping the faces of a right-handed helix consisting in 4 parallel beta-sheets - PB1, PB2a, PB2b and PB3 - separated by loops. The helix is closed at its N-terminal end by a <scene name='Sandbox_Reserved_711/N_terminal_alpha_helix/1'>small alpha-helix</scene>. | The endopolygalacturonase II from Aspergillus niger has a beta-helix structure<ref>http://www.ncbi.nlm.nih.gov/pubmed/10521427</ref>: the chain folds into 10 turns, shaping the faces of a right-handed helix consisting in 4 parallel beta-sheets - PB1, PB2a, PB2b and PB3 - separated by loops. The helix is closed at its N-terminal end by a <scene name='Sandbox_Reserved_711/N_terminal_alpha_helix/1'>small alpha-helix</scene>. | ||
