The M Protein of SARS-CoV: Basic Structural and Immunological Properties

Hu, Yongwu; Wen, Jie; Tang, Lin; Zhang, Haijun; Zhang, Xiaowei; Li, Yan; Wang, Jing; Han, Yujun; Li, Guoqing; Shi, Jianping; Tian, Xiangjun; Jiang, Feng; Zhao, Xiaoqian; Wang, Jun; Liu, Siqi; Zeng, Changqing; Wang, Jian; Yang, Huanming

The amino-terminal exterior region is composed of only 18 codons (including start codon), and is locally acidic (pI 4.20; hydrophobicity 33.3%; hydrophilicity 55.6%). A single putative glycosylation site is found at Codon 4 (NGTI). The carboxyl-terminal region is composed of 123 residues (56.1%) and is located in the interior. Three protein kinase C phosphorylation sites (SFR at Codon 98, TSR at Codon 171, SQR at Codon 183) and three N-myristoylation sites (GTIVTR at Codon 125, GTDSGF at Codon 187, GSNDNI at Codon 211) were predicted in this region. The putative glycosylation sites in the interior, as appearing in the M protein of HcoV-229E and PEDV, might be considered in relation to the orientation, even though it is very unlikely active (Fig. 2, Fig. 4, Fig. 5).