Escherichia coli O127 group 4 capsule proteins assemble at the outer membrane.
Escherichia coli O127 group 4 capsule proteins assemble at the outer membrane.
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DOI：
10.1371/journal.pone.0259900
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发表时间：
2021
期刊：
影响因子：
3.7
通讯作者：
Saper MA
中科院分区：
文献类型：
--
作者：
Larson MR;Biddle K;Gorman A;Boutom S;Rosenshine I;Saper MA
肠致病性大肠杆菌O 127被多糖保护层包裹，该多糖保护层由与血清型脂多糖相同的菌株特异性O-抗原制成。7个编码荚膜输出功能的基因组成第4组荚膜操纵子。基因gfcE、etk和etp编码组1荚膜分泌系统的同源物，但上游gfcABCD基因编码组4荚膜输出特异性的未知功能。我们已经开发了一个表达系统的大规模生产的外膜蛋白GfcD。与注释相反，我们发现GfcD是一种非酰化的整合膜蛋白。圆二色谱、光散射数据和HHomp服务器表明GfcD是具有26条β链和内部球状结构域的单体β桶。我们确定了一组新的GfcB，GfcC和GfcD之间的蛋白质-蛋白质相互作用，在体内和体外，并定量的结合性能与等温量热法和生物层干涉。GfcC和GfcB形成高亲和力异源二聚体，KD接近100 nM。该异源二聚体与GfcD的结合（KD = 28 μM）显著优于单独的GfcB或GfcC。这些gfc蛋白可以在外膜上形成复合物，用于第4组包膜分泌或用于未知的功能。
Enteropathogenic Escherichia coli O127 is encapsulated by a protective layer of polysaccharide made of the same strain specific O-antigen as the serotype lipopolysaccharide. Seven genes encoding capsule export functions comprise the group 4 capsule (gfc) operon. Genes gfcE, etk and etp encode homologs of the group 1 capsule secretion system but the upstream gfcABCD genes encode unknown functions specific to group 4 capsule export. We have developed an expression system for the large-scale production of the outer membrane protein GfcD. Contrary to annotations, we find that GfcD is a non-acylated integral membrane protein. Circular dichroism spectroscopy, light-scattering data, and the HHomp server suggested that GfcD is a monomeric β-barrel with 26 β-strands and an internal globular domain. We identified a set of novel protein-protein interactions between GfcB, GfcC, and GfcD, both in vivo and in vitro, and quantified the binding properties with isothermal calorimetry and biolayer interferometry. GfcC and GfcB form a high-affinity heterodimer with a KD near 100 nM. This heterodimer binds to GfcD (KD = 28 μM) significantly better than either GfcB or GfcC alone. These gfc proteins may form a complex at the outer membrane for group 4 capsule secretion or for a yet unknown function.
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影响因子：
3.7
作者：
Nadler C;Koby S;Peleg A;Johnson AC;Suddala KC;Sathiyamoorthy K;Smith BE;Saper MA;Rosenshine I
通讯作者：
Rosenshine I
DOI：
10.1073/pnas.1400341111
发表时间：
2014-06-03
影响因子：
11.1
作者：
Nickerson, Nicholas N.;Mainprize, Iain L.;Whitfield, Chris
通讯作者：
Whitfield, Chris
影响因子：
64.8
作者：
Jumper J;Evans R;Pritzel A;Green T;Figurnov M;Ronneberger O;Tunyasuvunakool K;Bates R;Žídek A;Potapenko A;Bridgland A;Meyer C;Kohl SAA;Ballard AJ;Cowie A;Romera-Paredes B;Nikolov S;Jain R;Adler J;Back T;Petersen S;Reiman D;Clancy E;Zielinski M;Steinegger M;Pacholska M;Berghammer T;Bodenstein S;Silver D;Vinyals O;Senior AW;Kavukcuoglu K;Kohli P;Hassabis D
通讯作者：
Hassabis D
影响因子：
2.8
作者：
Ferrieres, Lionel;Aslam, Shazia N.;Clarke, David J.
通讯作者：
Clarke, David J.
影响因子：
3.2
作者：
Peleg, A;Shifrin, Y;Rosenshine, I
通讯作者：
Rosenshine, I