Editing Protein structure (section)

===Tertiary structure===
{{Main|Protein tertiary structure}}
[[Tertiary structure]] refers to the three-dimensional structure created by a single protein molecule (a single [[polypeptide chain]]). It may include [[Protein domain|one or several domains]]. The α-helices and β-pleated-sheets are folded into a compact [[globular structure]]. The folding is driven by the ''non-specific'' [[hydrophobic interactions]], the burial of [[hydrophobic residues]] from [[water]], but the structure is stable only when the parts of a [[protein domain]] are locked into place by ''specific'' tertiary interactions, such as [[salt bridge (protein and supramolecular)|salt bridges]], hydrogen bonds, and the tight packing of side chains and [[disulfide bond]]s. The disulfide bonds are extremely rare in cytosolic proteins, since the [[cytosol]] (intracellular fluid) is generally a [[redox|reducing]] environment.