The Crystal Structure of Exfoliative Toxin B: A Superantigen with Enzymatic Activity
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- 作者：Gregory M. Vath ; Cathleen A. Earhart ; Dileep D. Monie ; John J. Iandolo ; Patrick M. Schlievert ; and Douglas H. Ohlendorf
- 刊名：Biochemistry
- 出版年：1999
- 出版时间：August 10, 1999
- 年：1999
- 卷：38
- 期：32
- 页码：10239 - 10246
- 全文大小：247K
- 年卷期：v.38,no.32(August 10, 1999)
- ISSN：1520-4995
文摘
The exfoliative toxins (ETs) cause staphylococcal scalded skin syndrome, a disease characterizedby specific separation of layers of the skin. Evidence suggests that the toxins act as serine proteases,though the specific substrate and mode of action are not known for certain. The crystal structure ofexfoliative toxin A (ETA) was reported earlier and shown to be similar to that of the chymotrypsin-likeserine proteases. Here, we report the 2.4 Å resolution crystal structure of the other exfoliative toxin, ETB,which is 40% identical to ETA. The overall structures of ETA and ETB are similar including the positionsof key residues within the active site. The structure of ETB supports the previous findings that the ETsare serine proteases that cleave substrates after glutamic acid residues. In this study we also discuss anumber of structural differences including a large 14 residue loop insertion which may be a key featureinvolved in the differing biological properties of the ETs, particularly the pyrogenic and lethal activitiesof ETB not shared by ETA.