What does HFU mean in UNCLASSIFIED

An HFU, or hydrophobic folding unit, is a group of amino acid residues that form a core in a folded protein. These residues tend to be hydrophobic, which helps to stabilize the folded structure of the protein.

HFUs are essential for proper functioning of a protein since they provide stability to its folded structure. Without this stability, proteins cannot fold properly and may not be able to fulfill their intended functions.

The hydrophobic residues form a core around which other more hydrophilic amino acids can be arranged so as to form stable tertiary structures. This ensures that when proteins fold, they maintain their correct structure and can carry out their intended function effectively.

In addition to providing stability to proteins through their interaction with other amino acid residues, HFUs also play important roles in catalyzing reactions and aiding certain metabolic pathways within the body. Moreover, they help regulate identification signals between cell membranes and proteins and thus enable cells to recognize each other correctly for proper communication within an organism's body system.

This depends on the complexity of the protein folds as well as its size; however typically one will find anywhere from several dozen to over one hundred individual HFUs comprising the entire 3D structure of any given protein molecule - smaller single-domain proteins will contain fewer than those with multiple domains or complex secondary structures respectively.