Search results
Results from the WOW.Com Content Network
Protein folding. Protein folding is the physical process by which a protein, after synthesis by a ribosome as a linear chain of amino acids, changes from an unstable random coil into a more ordered three-dimensional structure. This structure permits the protein to become biologically functional.
Protein secondary structure is the local spatial conformation of the polypeptide backbone excluding the side chains. [1] The two most common secondary structural elements are alpha helices and beta sheets, though beta turns and omega loops occur as well. Secondary structure elements typically spontaneously form as an intermediate before the ...
An alpha helix (or α-helix) is a sequence of amino acids in a protein that are twisted into a coil (a helix). The alpha helix is the most common structural arrangement in the secondary structure of proteins. It is also the most extreme type of local structure, and it is the local structure that is most easily predicted from a sequence of amino ...
A coiled coil is a structural motif in proteins in which 2–7 [1] alpha-helices are coiled together like the strands of a rope. (Dimers and trimers are the most common types.) They have been found in roughly 5-10% of proteins and have a variety of functions. [2] They are one of the most widespread motifs found in protein-protein interactions.
The three-helix bundle in the villin headpiece domain is only 36 amino acids long and is a common subject of study in molecular dynamics simulations because its microsecond -scale folding time is within the timescales accessible to simulation. [2][3] The 40-residue HIV accessory protein has a very similar fold and has also been the subject of ...
The Rossmann fold is a tertiary fold found in proteins that bind nucleotides, such as enzyme cofactors FAD, NAD +, and NADP +.This fold is composed of alternating beta strands and alpha helical segments where the beta strands are hydrogen bonded to each other forming an extended beta sheet and the alpha helices surround both faces of the sheet to produce a three-layered sandwich.
An alpha-helix with hydrogen bonds (yellow dots) The α-helix is the most abundant type of secondary structure in proteins. The α-helix has 3.6 amino acids per turn with an H-bond formed between every fourth residue; the average length is 10 amino acids (3 turns) or 10 Å but varies from 5 to 40 (1.5 to 11 turns). The alignment of the H-bonds ...
Supersecondary structure. A supersecondary structure is a compact three-dimensional protein structure of several adjacent elements of a secondary structure that is smaller than a protein domain or a subunit. Supersecondary structures can act as nucleations in the process of protein folding.