In any particular cell, most genes are expressed at a low level

Only a small number of genes, whose products are specialized for the cell type, are highly expressed.

mRNAs expressed at low levels overlap extensively when different cell types are compared.

The abundantly expressed mRNAs are usually specific for the cell type.

#Id: 7709

#Unit 1. Molecules and their Interaction Relevant to Biology

                              Type II β turn

#Id: 7710

#Unit 1. Molecules and their Interaction Relevant to Biology

#Id: 7711

#Unit 1. Molecules and their Interaction Relevant to Biology

                                                                 α-Turn

Contains hydrophilic amino acids and protrudes outside the protein surface like a hook.

Consists of 5 amino acids, generally termed as i, i+1, i+2, i+3 and i+4

H-bond is seen between i and i+4 (First and Fifth residue)

The conformation of i+1, i+2 and i+3 are crucial and on the basis of this, they are classified into

9 groups

#Id: 7712

#Unit 1. Molecules and their Interaction Relevant to Biology

                                                γ-Turn

Consists of 3 amino acids, generally termed as i, i + 1 and i + 2

H-bond is seen between i and i + 2 (First and Third residue)

The conformation of i + 1 is crucial and on the basis of this, they are classified into 2 groups

The dihedral angles of residue i + 1 are (70, -60) and (-70, 60) of the classical and inverse gamma turns

#Id: 7713

#Unit 1. Molecules and their Interaction Relevant to Biology

                                                        𝝅-Turn

Consists of 6 amino acids, generally termed as i, i + 1 , i + 2 i + 3 i + 4 and i + 5

H-bond is seen between i and i + 5 (First and sixth residue)

#Id: 8443

#Unit 1. Molecules and their Interaction Relevant to Biology