Protein Structure (Part 1)

Protein  Structure  (Part  1)  

Proteins  are  heteropolymers  

•  hetero  –  (from  Greek)  other,  another  different  •  polymer  –  a  molecule  consis=ng  of  repea=ng  units  

20  Naturally  occurring  amino  acids  

•  differ  in  the  nature  of  their  “sidechains”  

•  these  proper=es,  and  the  sequence  in  which  they  occur  determine  the  “shape”  of  the  protein  

Protein  Structure  Heirarchy  

…AGARTWLYLIPDNLDK…   Primary  structure  

Secondary  structure  α  helix   β  sheet  

Ter=ary  structure  

Quaternary  structure   Increasing  Com

plexity

Helices  and  Sheets  

Repea=ng  units  of  secondary  structure  that  allow  for  regular  networks  of  hydrogen  bonds  between  backbone  atoms.  

Go  to  Protein  Structure  Worksheet  and  get  some  hands-­‐on  experience  looking  at  protein  structures!  

Protein  Structure  Links  

•  PDB  (Protein  Data  Bank):  – hZp://www.pdb.org  

•  SCOP  (Structural  Classifica=on  of  Proteins)  – hZp://scop.mrc-­‐lmb.cam.ac.uk/scop/  

•  CATH  (Protein  Structure  Classifica=on  Database)  – hZp://www.cathdb.info/