From Proteopedia

Adenylate Kinase

is a enzyme that catalyzes the conversion of 2 units of ADP into a unit of ATP and a unit of AMP. It is because of this catalytic role that adenylate kinase is an important part of homeostasis. Consisting of only 211 amino acids, adenylate kinase is not that large of an enzyme, despite its vital role in metabolism.

Structure

The of adenylate kinase shows alpha helices (blue) and beta sheets (teal) surrounding the non-hydrolysable substrate analogue. The enzyme is comprised of 9 helices and 9 sheets constituting the secondary structure. As with any enzyme, the (May not load) between the residues of the peptide chains supply the final folded protein with structural stability which helps hold it in its folded configuration.

This secondary structure is oriented as such so that the are buried or exposed depending on their individual properties. The hydrophobic, represented in grey, are buried as to avoid as much contact with water as possible. Similarly, the hydrophilic, or polar, residues are colored purple and exposed as much to water as possible. This is further illustrated by the model, displaying water molecules as pink orbs and the enzyme as a translucent white. These hydrophobic interactions, burying of non polar residues and exposure of polar ones, is another main driving force conserving the tertiary structure of the enzyme.

The model of adenylate kinases shows displays the non-hydrolysable substrate as the ligand. The are polar as the substrate is also highly negatively charged. The ligand can be seen in the active site of the enzyme, and shown in standard atomic coloring scheme. The are the residues that directly interact with the ligand, and can be seen in yellow.