Protein Motifs Flashcards
What is a protein motif
Arrangements of limited numbers of secondary structure elements
Form part of larger regions of proteins-domains
In multi-domain proteins each domain has a role
What are ß-α-ß motifs
Found in almost every structure that contains parallel b-sheet
a-helix connects the C-terminus of one b-strand with the N-terminus of a second
b-a-b contains two b-strands, two loop regions and one a-helix.
Can be found in larger, repeating domains
Found in repeating units in proteins
What are some different types of protein motifs
Helix-loop-helix
Zinc finger
EF hand motif
Greek key motif
b-a-b motif
Leucine rich motif
Rossman fold
What is y- crystallin
Y-crystallin protein is in lens of the eye
Responsible in part for transparency and refractive power
Contains 2 domains
Each domain contains two Greek key motifs
what is the structure of a pyruvate uinase
530 amino acids
Tetramer, only a monomer is shown
4 different domains
N-terminal domain key in oligomer formation
a/b barrel is core functional domain
Why are proteins multi domain
One suggestion is that it makes evolving new proteins easier- Easier than single point mutations
A domain in one protein can be transposed to another protein-should do the same job
Multidomain organisation makes it easy to introduce control and regulation
Multidomain construction simplifies folding and assembly
Stabilizes the protein
Large single domain protein would take a long time to fold
Domains fold independently
What can domains be
Domains can be a-helical, b-strand or a mixture of both.
Why are oligomers important
Important for function
Stabilises proteins
Cooperativity
What are the characteristics of protein motifs
What is a helix-loop-helix motif
What do transcription factors do
What is the zinc finger domain
What is a 4 helix bundle motif
What are the 2 different ways for a 4 helix bundle to be arranged
What is the EF hand motif
What is a Greek key motif
