[Codon Bias Analysis in the Coding Genes of Structural and Accessory Proteins of Middle East Respiratory Syndrome Coronavirus].

Middle East respiratory syndrome coronavirus (MERS-Co V) is a RNA virus causing serious harm to people. In order to investigate the codon usage characteristics and influence factors, codon preference and multivariate statistical analysis of MERS-Co V 9 gene sequences were performed by using Codon W, CUSP and SPSS software, getting the content of GC at three positions of codons, ENC (Effective number of codon)and RSCU(Relative synonymous codon usage)of all genes. In addition, the results were compared with Escherichia coli, yeast and human’s codon usage frequency. The results showed that GC3 content is significantly lower than GC1 and GC2content,and less than 50%.It indicates that the third position of codons prefers to A or T.ENC value is 50.59,which implies codon usage bias is a little slight in MERS-Co V genome. According to the neutral drawing analysis and ENC-plot analysis, codon bias is mainly affected by selection pressure in the MERS-Co V genome. It is found that codon usage frequency of MERS-Co V is more close to yeast, compared with other three kinds of biological codon usage frequency.Finally,19 codons are defined as the major preference codons in MERS-Co V. The results have a certain significance for MERS-Co V that selecting gene expression host system, contributing further to development of genetically engineered vaccine and therapeutic antibody.