The Structure Analysis and Antigenicity Study of the N Protein of SARS-CoV

Wang, Jingqiang; Ji, Jia; Ye, Jia; Zhao, Xiaoqian; Wen, Jie; Li, Wei; Hu, Jianfei; Li, Dawei; Sun, Min; Zeng, Haipan; Hu, Yongwu; Tian, Xiangjun; Tan, Xuehai; Xu, Ningzhi; Zeng, Changqing; Wang, Jian; Bi, Shengli; Yang, Huanming

The SR-rich region has been found in all coronavirus N proteins. However, it is not within conserved regions that we have detected this region from similarity analysis. Further study showed that this region is relatively variable. For example, in the N protein of SARS-CoV, there is a substitution in SR-rich region. Therefore, we used SR as a marker to identify this region, though amino acid change may occur in SR and cause marker to disappear. We classified all SR-rich regions of coronavirus N proteins into a few types (Table 2), and discovered that the classification of those coronaviruses by their core motifs of the SR-rich region was consistent with the phylogenic tree that we had constructed. It seems that the SR-rich region is typically common and representative, though it is outside the conserved regions and has easily-varied sequence.