Study of kinetics of complex coacervation occurring in aqueous 1-octyl-3-methylimidazolium chloride ionic liquid solution of low charge density polypeptide (gelatin A) and 200 base pair DNA, and thermally activated coacervate into anisotropic gel transition, is reported here. Associative interaction between DNA and gelatin A (GA) having charge ratio (DNA:GA = 16:1) and persistence length ratio (5:1) was studied at fixed DNA (0.005% (w/v)) and varying GA concentration (C-GA = 0-0.25% (w/v)). The interaction profile was found to be strongly hierarchical and revealed three distinct binding regions: (i) Region I showed DNA-condensation (primary binding) for C-GA < 0.10% (w/v), the DNA zeta potential decrease from -80 to -5 mV (95%) (partial charge neutralization), and a size decrease by approximate to 60%. (ii) Region II (0.10 < C-GA < 0.15% (w/v)) indicated secondary binding, a 4-fold turbidity increase, a zeta potential decrease from -5 to 0 mV (complete charge neutralization), which resulted in the appearance of soluble complexes and initiation of coacervation. (iii) Region III (0.15 < C-GA < 0.25% (w/v)) revealed growth of insoluble complexes followed by precipitation. The hydration of coacervate was found to be protein concentration specific in Raman studies. The binding profile of DNA-GA complex with IL concentration revealed optimum IL concentration (=0.05% (w/v)) was required to maximize the interactions. Small angle neutron scattering (SANS) data of coacervates gave static structure factor profiles, 1(q) versus wave vector q, that were remarkably similar and invariant of protein concentration. This data could be split into two distinct regions: (i) for 0.0173 < q < 0.0353 angstrom(-1), I(q) similar to q(-a) with alpha = 1.35-1.67, and (ii) for 0.0353 < q < 0.35 angstrom(-1), I(q) = I(0)/(1 + q(2)xi(2)). The correlation length found was xi = 2 +/- 0.1 nm independent of protein concentration. The viscoelastic length (approximate to 8 nm) was found to have value close to the persistence length of the protein (approximate to 10 nm). Rheology data indicated that the coacervate phase resided close to the gelation state of the protein. Thus, on a heating-cooling cycle (heating to 50 degrees C followed by cooling to 20 degrees C), the heterogeneous coacervate exhibited an irreversible first-order phase transition to an anisotropic ion gel. This established a coacervate-ion gel phase diagram having a well-defined UCST.