到2013年7月中旬,，被最近出現(xiàn)的類似SARS的“中東呼吸綜合癥冠狀病毒” (MERS-CoV) 感染的90個病例已被確認,，其中包括43個死亡病例,。ACE2 (angiotensin converting enzyme 2) 對SARS冠狀病毒起一個細胞表面受體的作用,，但MERS-CoV的功能受體是“二肽基肽酶-4”,，亦稱為CD26,。這篇論文介紹了MERS-CoV刺突蛋白的受體結(jié)合域的晶體結(jié)構(gòu)（包括自由狀態(tài)和與該受體相結(jié)合狀態(tài)的結(jié)構(gòu)）,。這些結(jié)構(gòu)顯示了一個“核心子域”，與SARS-CoV刺突蛋白的“核心子域”同源,，同時還顯示了一個獨特的,、由鏈支配的（strand-dominated）外部受體結(jié)合主題，其作用是識別CD26,。一個適當折疊的“受體結(jié)合域”也許具有用在一種MERS-CoV疫苗中,、充當一個“免疫原”的潛力。（生物谷 Bioon.com）
生物谷推薦的英文摘要
Nature doi:10.1038/nature12328
Molecular basis of binding between novel human coronavirus MERS-CoV and its receptor CD26
Guangwen Lu, Yawei Hu, Qihui Wang, Jianxun Qi, Feng Gao, Yan Li, Yanfang Zhang, Wei Zhang, Yuan Yuan, Jinku Bao, Buchang Zhang, Yi Shi, Jinghua Yan & George F. Gao
The newly emergent Middle East respiratory syndrome coronavirus (MERS-CoV) can cause severe pulmonary disease in humans1, 2, representing the second example of a highly pathogenic coronavirus, the first being SARS-CoV3. CD26 (also known as dipeptidyl peptidase 4, DPP4) was recently identified as the cellular receptor for MERS-CoV4. The engagement of the MERS-CoV spike protein with CD26 mediates viral attachment to host cells and virus–cell fusion, thereby initiating infection. Here we delineate the molecular basis of this specific interaction by presenting the first crystal structures of both the free receptor binding domain (RBD) of the MERS-CoV spike protein and its complex with CD26. Furthermore, binding between the RBD and CD26 is measured using real-time surface plasmon resonance with a dissociation constant of 16.7 nM. The viral RBD is composed of a core subdomain homologous to that of the SARS-CoV spike protein, and a unique strand-dominated external receptor binding motif that recognizes blades IV and V of the CD26 β-propeller. The atomic details at the interface between the two binding entities reveal a surprising protein–protein contact mediated mainly by hydrophilic residues. Sequence alignment indicates, among betacoronaviruses, a possible structural conservation for the region homologous to the MERS-CoV RBD core, but a high variation in the external receptor binding motif region for virus-specific pathogenesis such as receptor recognition.
