Polygalacturonase: Difference between revisions
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<Structure load='1czf' size='350' frame='true' align='right' caption='Secondary structure of ''endo''-polygalacturonase II' scene='Insert optional scene name here' />Polygalacturonases (PGs) catalyze the enzymatic depolymerization of | <Structure load='1czf' size='350' frame='true' align='right' caption='Secondary structure of ''endo''-polygalacturonase II' scene='Insert optional scene name here' />Polygalacturonases (PGs) catalyze the enzymatic depolymerization of pectates – polysaccharides that comprise the plant cell wall. Polymer disassembly of substrates by ''exo-'' and ''endo-'' PGs is carried out via a hydrolytic mechanism. Degradation of pectates in plant cell walls contributes to ripening of fruits, such as tomatoes and melons (Polygalacturonases: many genes in search of a function). Microbial PGs have been identified to be a part of defense mechanisms because of their role in pathogen attack (crystal structure). | ||
--MDY -- this is a bit confusing. PG's are found in bacteria, fungi, plants, and animals. Plant PG's are involved in fruit ripening. Bacteria and fungal PG are involved in plant pathogenesis, often acting as plant virulence factors and involved in some of the initial pathogenic effects through their action of degrading the plant cell wall. -- MDY | --MDY -- this is a bit confusing. PG's are found in bacteria, fungi, plants, and animals. Plant PG's are involved in fruit ripening. Bacteria and fungal PG are involved in plant pathogenesis, often acting as plant virulence factors and involved in some of the initial pathogenic effects through their action of degrading the plant cell wall. -- MDY | ||
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== Relevance == | == Relevance == | ||
== Structural highlights == | == Structural highlights == | ||
The | The tertiary fold of PGs varies in its composition of coils, approximating at 10 coils in a right-handed parallel beta helix domain along with loop regions that together form the substrate-binding cleft, which appears to have a tunnel-like shape. The active site of PGs is found between the looped regions of the protein. Located within the looped regions are two conserved aspartate residues that are predicted to participate in catalytic activity (crystal structure). | ||
MDY- a right-handed parallel beta helix is a tertiary fold. The secondary structure is the beta and the alpha structure. If you describe how the secondary structure folds in space, that becomes tertiary structure. The secondary structural elements of the core fold of the proteins are only beta structure, the beta strands form parallel beta sheets. There are three main parallel beta sheets, PG's often have a smaller parallel beta sheet of only three-four beta strands. | MDY- a right-handed parallel beta helix is a tertiary fold. The secondary structure is the beta and the alpha structure. If you describe how the secondary structure folds in space, that becomes tertiary structure. The secondary structural elements of the core fold of the proteins are only beta structure, the beta strands form parallel beta sheets. There are three main parallel beta sheets, PG's often have a smaller parallel beta sheet of only three-four beta strands. | ||
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== References == | == References == | ||
<references/> | <references/> | ||
<ref>DOI: 10.1074/jbc.273.38.24660 | |||
