   3.5.1.124 | dimer |
VcHsp31 acquires two (type-I and type-II) dimeric forms. Type-I dimer is similar to EcHsp31 where two VcHsp31 monomers associate in eclipsed manner through several intersubunit hydrogen bonds involving their P-domains. Type-II dimer is a dimeric organization, where some of the intersubunit hydrogen bonds are abrogated and each monomer swings out in the opposite directions centering at their P-domains, like twisting of wet cloth. Normal mode analysis (NMA) of type-I dimer shows similar movement of the individual monomers. Upon swinging, a dimeric surface of 400 A2, mostly hydrophobic in nature, is uncovered which might bind partially unfolded protein substrates. It is proposed that, in solution, VcHsp31 remains as an equilibrium mixture of both the dimers. With increase in temperature, transformation to type-II form having more exposed hydrophobic surface, occurs progressively accounting for the temperature dependent increase of chaperone activity of VcHsp31 |
-, 755138 |
