There are 20 different amino acids that proteins can be made from. These twenty amino acids are grouped into three categories based on the nature of their side group (R): 1) hydrophilic amino acids with a charged or polar and uncharged R group 2) hydrophobic amino acids with a aliphatic or bulky and aromatic R group and 3) amino acids with a special group consisting of cysteine, glycine, and proline.
The most common elements found in a protein's secondary structure is an alpha helix, a beta sheet, strand and turn. The protein's secondary structure is stabilized by hydrogen bonds between atoms of the peptide backbone.Different combinations of secondary structures give rise to different motifs which are found in a variety of proteins and often are associated with specific functions.
A Protein tertiary structure is a result of hydrophobic interactions and disulfide bonds that stabilize folding of the secondary structure into a compact overall conformation. Distinct domains are found in large proteins, these are independently folded regions of tertiary structure with characteristic structural and or functional properties.
The organization and number of subunits in multimeric proteins makes up a protein’s quaternary structure.
A proteins sequence determines is 3D structure which in turn determines its function. display_block('protein_features'); ?>