title: Translocators YopB and YopD from Yersinia enterocolitica form a multimeric integral membrane complex in eukaryotic cell membranes.
abstract: The type III secretion systems are contact-activated secretion systems that allow bacteria to inject effector proteins across eukaryotic cell membranes. The secretion apparatus, called injectisome or needle complex, includes a needle that terminates with a tip structure. The injectisome exports its own distal components, like the needle subunit and the needle tip. Upon contact, it exports two hydrophobic proteins called translocators (YopB and YopD in Yersinia enterocolitica) and the effectors. The translocators, assisted by the needle tip, form a pore in the target cell membrane, but the structure of this pore remains elusive. Here, we purified the membranes from infected sheep erythrocytes, and we show that they contain integrated and not simply adherent YopB and YopD. In blue native PAGE, these proteins appeared as a multimeric 500- to 700-kDa complex. This heteropolymeric YopBD complex could be copurified after solubilization in 0.5% dodecyl maltoside but not visualized in the electron microscope. We speculate that this complex may not be stable and rigid but only transient.
authors: Biozentrum der Universität Basel, Basel, Switzerland.
authors: Caroline
authors: C
authors: Montagner
authors: Christian
authors: C
authors: Arquint
authors: Guy R
authors: GR
authors: Cornelis
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000737:chemistry / Q000382:microbiology*; D004912:Erythrocytes / Q000737:chemistry / Q000382:microbiology*; D008970:Molecular Weight; D046912:Multiprotein Complexes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D012756:Sheep; D012757:Sheep Diseases / Q000382:microbiology*; D015009:Yersinia Infections / Q000382:microbiology / Q000662:veterinary*; D015008:Yersinia enterocolitica / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D046912:Multiprotein Complexes; C078909:YopB protein, Yersinia; C078910:YopD protein, Yersinia