Quart Complexes Flashcards
What is the pyruvate dehydrogenase complex made of
3 enzymes
Name the 3 enzymes that make up pyruvate dehydrogenase complex
Pyruvate dehydrogenase (E1), Dihydrolipoyl transacetylase (E2), Dihydrolipoyl dehydrogenase (E3)
Describe the size of PDH complex in mammals
50nm in diameter and 5 times bigger than entire ribsome
How is the substrate of PDH channelled?
Via a swinging arm action of lipoyllysyl of E2
what is a multimer?
a multisubunit protein
Multimeric proteins can have how many subunits
from 2 to 100 subunits
What is an ogliomer
Multimer with just a few subunits
What is the repeating structural unit in a multimeric protein called
Protomer
Ogliomers can have what type of symmetry?
rotational or helical
Describe rotational/helical symmetry
subunits can be superimposed on others by rotation about one or more rotational axes or by a helical rotation
describe the difference between rotational and helical symmetry in proteins
Proteins with rotational symmetry have subunits that are closely packed to form closed structures.
Proteins with helical symmetry tend to form structures that are more open-ended with spiral form.
Name 3 types of rotational symmetry
cyclic, dihedral and icosahedral
Describe cyclic symmetry
- rotation about a single axis
- Cn
- axis is described as an n-fold roational axis
Describe dihedral symmetry
- twofold rotational axis intersects an n fold axis at right angles
- Dn
- 2n protomers
Describe icosahedral symmetry
- Regular 12 cornered polyhedron have 20 equilateral triangular faces
