Study Of The Symmetry In The Primary Sequences Of Beta-barrel Family And TIM-barrel Family

In the mid 1950's, Anfinsen proposed a famous judgment that the tertiary structure of a protein is determined by its amino acid sequence. That is to say, all the information of the tertiary structure is hidden in the primary sequence. Investigating the primary sequence has very important meaning on understanding the relationship between the primary and tertiary structure and also plays a significant role in the structure prediction. Thus, analyses the primary sequence, abstract the information of structure and function, study the relationship between primary and tertiary structure, has become the knowledge, which biologists eager to understand and mast. They are also the important task of the molecule biology.The nature of the relationship between amino acid sequence and the 3D structure of a protein has been a topic of intense interest for some time, but in many ways it is still an unsolved problem. Although it is generally accepted that amino acid sequence determines 3D structure, how structural information is mapped onto a linear sequence is only partially understood.In this paper, we focus on the analysis of the primary sequence. Firstly, we study the relationship between the primary and tertiary structure on the facet on symmetric. The results suggest that the primary sequence has the same symmetries as their tertiary structure. Factors such as secondary structure propensities clearly play a role, as do the positions of polar and non-polar residues along the sequence,we reduced the complexity of protein sequence by residue grouping, according to their chemical and physical property. We used the method of the modified recurrent quantification and analysis the Beta-barrel family to find the hidden symmetries of the primary sequences as their tertiary structures. In this method, we also test the result by p-value and the result is considered significant. The result that all of the typical sequences have the two-fold symmetry may provide new insights into the symmetries of the protein structures. In odder to validate our method in further, we study the TIM-barrel family and find the multiple symmetry based on the two-fold symmetry. Meanwhile we predict the conserved residues in isomerase (pdbid: 1qo2).