Question

1. Explain the secondary structure of protein
with examples. ​

Answer 1

Answer:

protein secondary structure is the three dimensional form of local segments of proteins. 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 protein folds into its three dimensional tertiary structure.

Secondary structure is formally defined by the pattern of hydrogen bonds between the amino hydrogen and carboxyl oxygen atoms in the peptide backbone. Secondary structure may alternatively be defined based on the regular pattern of backbone dihedral angles in a particular region of the Ramachandran plot regardless of whether it has the correct hydrogen bonds.

SST is a Bayesian method to assign secondary structure to protein coordinate data using the Shannon information criterion of Minimum Message Length (MML) inference. SST treats any assignment of secondary structure as a potential hypothesis that attempts to explain (compress) given protein coordinate data. The core idea is that the best secondary structural assignment is the one that can explain (compress) the coordinates of a given protein coordinates in the most economical way, thus linking the inference of secondary structure to lossless data compression. SST accurately delineates any protein chain into regions associated with the following assignment types:[12]

E = (Extended) strand of a β-pleated sheet

G = Right-handed 310 helix

H = Right-handed α-helix

I = Right-handed π-helix

g = Left-handed 310 helix

h = Left-handed α-helix

i = Left-handed π-helix

3 = 310-like Turn

4 = α-like Turn

5 = π-like Turn

T = Unspecified Turn

C = Coil

- = Unassigned residue

The concept of secondary structure was first introduced by Kaj Ulrik Linderstrøm-Lang at Stanford in 1952.Other types of biopolymers such as nucleic acids also possess characteristic secondary structure

Explanation: