Departamento de Salud Pública Facultad de Medicina UNAM, Ciudad Universitaria Coyoacán 04510, D.F., Mexico; Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato Oncología e Investigación, Hospital Infantil de México Federico Gómez 06720, D.F., Mexico.
Department of Chemistry and Biochemistry, Arizona State University, Physical Sciences BLDG D-102, Tempe, AZ 85287, USA.
Biochem Biophys Res Commun. 2014 Mar 7;445(2):439-44. doi: 10.1016/j.bbrc.2014.02.016. Epub 2014 Feb 12.
Autotransporters (ATs) represent a superfamily of proteins produced by a variety of pathogenic bacteria, which include the pathogenic groups of Escherichia coli (E. coli) associated with gastrointestinal and urinary tract infections. We present the first X-ray structure of the passenger domain from the Plasmid-encoded toxin (Pet) a 100 kDa protein at 2.3 Å resolution which is a cause of acute diarrhea in both developing and industrialized countries. Pet is a cytoskeleton-altering toxin that induces loss of actin stress fibers. While Pet (pdb code: 4OM9) shows only a sequence identity of 50% compared to the closest related protein sequence, extracellular serine protease plasmid (EspP) the structural features of both proteins are conserved. A closer structural look reveals that Pet contains a β-pleaded sheet at the sequence region of residues 181-190, the corresponding structural domain in EspP consists of a coiled loop. Secondary, the Pet passenger domain features a more pronounced beta sheet between residues 135 and 143 compared to the structure of EspP.
自动转运蛋白（ATs）是一类由多种致病菌产生的蛋白超家族，其中包括与胃肠道和尿路感染相关的致病性大肠杆菌（E. coli）群体。我们首次解析了质粒编码毒素（Pet）乘客结构域的 X 射线结构，该毒素分子量为 100kDa，分辨率为 2.3Å，是发展中国家和工业化国家急性腹泻的致病因素。Pet 是一种改变细胞骨架的毒素，可诱导肌动蛋白应力纤维的丧失。虽然 Pet（pdb 编号：4OM9）与最接近的相关蛋白序列，即细胞外丝氨酸蛋白酶质粒（EspP）相比，只有 50%的序列同一性，但这两种蛋白质的结构特征是保守的。更仔细的结构观察表明，Pet 在残基 181-190 处的序列区域包含一个β折叠片，而 EspP 中的相应结构域由一个卷曲环组成。其次，与 EspP 的结构相比，Pet 乘客结构域在残基 135 和 143 之间具有更明显的β片层。
