2021 Volume 61 Issue 1 Pages 005-011
The Snake Cube Puzzle made of a linear array of 27 cubes and its modified and extended versions are used as theoretical models to study the mechanism of folding of proteins into their sequence-specific native three-dimensional structures. The problem of protein folding is reviewed very briefly by comparing it with the problem of genetic code. It is stressed that the folding process is basically a physical phenomenon. The consistency principle advocated nearly 40 years ago to explain the folding mechanism is briefly reviewed. The result obtained by using the models provides a semi-quantitative manifestation of the consistency principle.