Lecture 6 - protein structure and folding Flashcards
what is the building of a tertiary protein structure
secondary structure, supersecondary structure and protein domains
what is a supersecondary structure
several adjacent elements of a secondary structure that is smaller than a protein domain
examples of supersecondary structures
helix - turn - helix , beta hairpin, greek key, strand - helix - strand
what do supersecondary structures combine to form
domains
what are domains
independentley folded regions that often possess a specific function
what is a hydrophobic core of a protein domain important for
very important for protein stability
where are the hydrophilic parts arranged in protein domains
on the surface in contact or near the solvent
how many domains do small proteins usually have
usually one
how many domains do larger proteins have
may have multiple domains
what are three examples of how proteins can be grouped into families based on tertiary structure
- a domain family
- a/B family
- anitparallel B family
properties of an a domain family
mostly helical with a hydrophobic core
properties of an a/B domain family
mix of a and b structure
- a/b barrel
- a/b horseshoe fold
properties of an antiparallel B family
mostly antiparallel b structure
- often for transporting things like vitamin A
what did Anfinsen’s experiment show
all the information needed for a protein to fold for its function is in the linear amino acid sequence
what is the likely sequence of events in folding a newly synthesised protein
- formation of short secondary segments (alpha helices and beta strands)
- subdomains form (supersecondary structure)
- subdomains come together to form loose domains
- final domain structure emerges, small conformational adjustments to give overall tertiary structure
