Network Biology, 2021, 11(3): 125-136 IAEES www.iaees.org Article Analysis of amino acids network based on transition and transversion mutation of codons Tazid Ali, Chandra Borah Department of Mathematics, Dibrugarh University, Assam 786004, India E-mail: tazid@dibru.ac.in, chandra92borah@gmail.com Received 12 March 2021; Accepted 29 March 2021; Published 1 September 2021 Abstract In this paper, we have developed a network of 20 amino acids based on a distance matrix of amino acids. This distance matrix is obtained by considering the transition and transversion mutation of codons. We have proposed that the evolutionary pattern of amino acids is reflected throughout this network. We have discussed different measures of centrality: degree centrality, closeness centrality, betweenness centrality and eigenvector centrality, concerning this network and investigated the comparative impact of the amino acids. We have also explored the correlation coefficients between the different centrality measures checking the assortativity of the network. Further, we have explored three network parameters: namely clustering coefficient, degree of distribution and skewness. Keywords amino acids; genetic code; centrality measure; correlation coefficient; network parameter; distance matrix. 1 Introduction All life forms in existence are composed of cells. In each cell, there is a set of chromosomes that serves as a blueprint for the whole life entity. A chromosome consists of genes (sequence of DNA), where a gene encodes a specific protein. A protein consists of a linear sequence of amino acids, the essential building blocks and functional components of living organisms. Twenty different amino acids have been found to date that exists in proteins. The three sequencing bases is a unit called a codon that specifies an amino acid. Since there are four bases, that give us a total of 64 codons. So, there must be some similarity, i.e., more than one codon code for the same amino acid. Codons that code for the same amino acids are classified as synonymous codons. This can be observed as a mapping of many to one taking codons to amino acids. Also, out of these 64 codons, UAA, UAG and UGA triplets are known as stop codons, and their task is to terminate the translation process. The flow of information from DNA to protein is carried out via transcription and translation (Shu, 2017). As a consequence of mutation, the sequencing bases are not duplicated exactly in replicating the DNA strand. Network Biology ISSN 22208879 URL: http://www.iaees.org/publications/journals/nb/onlineversion.asp RSS: http://www.iaees.org/publications/journals/nb/rss.xml Email: networkbiology@iaees.org EditorinChief: WenJun Zhang Publisher: International Academy of Ecology and Environmental Sciences