Tertiary structure

Relationship to primary sequence

Tertiary structure is considered to be largely determined by the protein's protein structure prediction. However, the environment in which a protein is synthesized and allowed to fold are significant determinants of its final shape and are usually not directly taken into account by current prediction methods. (Most such methods do rely on comparisons between the sequence to be predicted and sequences of known structure in the Protein Data Bank and thus account for environment indirectly, assuming the target and template sequences share similar cellular contexts.) A large-scale experiment known as CASP directly compares the performance of state-of-the-art prediction methods and is run once every two years.

Determinants of tertiary structure

In alpha helices. Proteins are classified by the folds they represent in databases like SCOP and CATH.

Not every polypeptide chain has a well-defined tertiary structure. Some proteins, especially short proteins, are natively disordered and exist as domains whose relative orientation can change depending on the environment.

Stability of native states

The most typical conformation of a protein in its cellular environment is generally referred to as the translated is small.

In the cell, a variety of protein Heat shock proteins Hsp60/Hsp10 system fall into this category.

Some proteins explicitly take advantage of the fact that they can become kinetically trapped in a relatively high-energy conformation due to folding kinetics. Influenza pH, the protein undergoes an energetically favorable conformational rearrangement that enables it to penetrate a host cell membrane.

Experimental determination

The majority of protein structures known to date have been solved with the experimental technique of X-ray membrane proteins because the latter class is extremely difficult to study using these methods.

History

Since the tertiary structure of proteins is an important problem in biochemistry, and since structure determination is relatively difficult, secondary structure predictions.^{[citation needed]}

See also

• Folding (chemistry)
• primary structure
• secondary structure
• quaternary structure
• structural biology

References

1. ^ International Union of Pure and Applied Chemistry. "tertiary structure". Compendium of Chemical Terminology Internet edition.