Enzyme introduction Flashcards
What are CAZymes?
Carbohydrate active enzymes
What are carbohydrate-active enzymes?
Enzymes that degrade, modify, or synthesise carbohydrates
What are the 5 different classes of cazymes?
Polysaccharide lyases Glycoside hydrolases Carbohydrate esterases Lytic polysaccharides monooxygenases Glycosyl transferases
What do polysaccharide lyases do?
Break the glycosidic bond by a β elimination mechanism
What do glycoside hydrolases do?
Break the glycosidic bond through hydrolysis with the addition of water
What do carbohydrate esterases do?
Remove modifications from different sugars is acetate or methyl groups
What do lytic polysaccharides monooxygenases do?
Cleave the glycosidic bond by oxidative mechanism and are Cu dependent
What do glycosyl transferases do?
Synthesis glycosidic bonds
How does CAZy organise information?
Groups enzymes into sequence-based families
Specificities within families can be highly variable
What is conserved within families?
Fold, catalytic apparatus, and mechanisms are conserved within families
How many families are there in GH?
168
How many families are there in PL?
40
How many families are there in CE?
18
How many families are there in non-catalytic carbohydrate-binding modules?
87
How many families are there in Auxilary activities?
16
How many families are there in LPMO?
6
How many families are there in GT?
111
What 2 ways of acting can GH be classified as?
Endo or exo acting
Describe endo acting GHs
They cleave the glycosidic bond in the middle of the chain releasing oligosaccharides
Describe exo acting GHs
They cleave the glycosidic bond at the end of the chain releasing a monosaccharide
They normally work from the non-reducing end of a polysaccharide but some work from the reducing end
What 2 ways of cleaving mechanism can GH be classified as?
Retaining or inverting
Describe retaining GHs
They retain the anomeric configuration of the glycosidic bond
Describe inverting GHs
They invert the anomeric configuration of the glycosidic bond
