Approaches to prediction of protein structure

Protein structure prediction (PSP) is one of the most important and challenging problems in bioinformatics today. This is due to the fact that the biological function of the protein is determined by its structure. While there is a gap between the number of known protein sequences and the number of known structures, protein structure prediction aims at reducing this sequence-structure gap. Protein structure can be experimentally determined using either X-ray crystallography or Nuclear Magnetic Resonance (NMR). However, these empirical techniques are very time consuming, so computational models and the associated algorithms have been developed for protein structure prediction. Such computational models fall into three categories: the homology approach, threading, and the ab initio approach. In this paper we give a general introductory background to the area and a literature survey about the ab initio approach in particular. This approach depends on the chemical and physical properties of the constituent amino acids. Not all ab initio algorithms have the same performance, so we represent the general success keys for any such algorithm.