title: AatA is a novel autotransporter and virulence factor of avian pathogenic Escherichia coli.
abstract: Autotransporters (AT) are widespread in Gram-negative bacteria, and many of them are involved in virulence. An open reading frame (APECO1_O1CoBM96) encoding a novel AT was located in the pathogenicity island of avian pathogenic Escherichia coli (APEC) O1's virulence plasmid, pAPEC-O1-ColBM. This 3.5-kb APEC autotransporter gene (aatA) is predicted to encode a 123.7-kDa protein with a 25-amino-acid signal peptide, an 857-amino-acid passenger domain, and a 284-amino-acid beta domain. The three-dimensional structure of AatA was also predicted by the threading method using the I-TASSER online server and then was refined using four-body contact potentials. Molecular analysis of AatA revealed that it is translocated to the cell surface, where it elicits antibody production in infected chickens. Gene prevalence analysis indicated that aatA is strongly associated with E. coli from avian sources but not with E. coli isolated from human hosts. Also, AatA was shown to enhance adhesion of APEC to chicken embryo fibroblast cells and to contribute to APEC virulence.
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, 1802 University Blvd., Iowa State University, Ames, IA 50011, USA.
authors.forename: Ganwu
authors.initials: G
authors.lastname: Li
authors.forename: Yaping
authors.initials: Y
authors.lastname: Feng
authors.forename: Subhashinie
authors.initials: S
authors.lastname: Kariyawasam
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Tivendale
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Wannemuehler
authors.forename: Fanghong
authors.initials: F
authors.lastname: Zhou
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Logue
authors.forename: Cathy L
authors.initials: CL
authors.lastname: Miller
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Nolan
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001422:Bacterial Adhesion; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D002462:Cell Membrane / Q000737:chemistry; D002478:Cells, Cultured; D002645:Chickens; D003593:Cytoplasm / Q000737:chemistry; D004926:Escherichia coli / Q000737:chemistry / Q000302:isolation & purification / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D005347:Fibroblasts / Q000382:microbiology; D017353:Gene Deletion; D005816:Genetic Complementation Test; D044404:Genomic Islands; D006801:Humans; D008856:Microscopy, Fluorescence; D008970:Molecular Weight; D010957:Plasmids; D011201:Poultry Diseases / Q000382:microbiology*; D021382:Protein Sorting Signals; D017434:Protein Structure, Tertiary; D014774:Virulence; D037521:Virulence Factors / Q000502:physiology*
chemical_list: C512825:AatA protein, E coli; D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D021382:Protein Sorting Signals; D037521:Virulence Factors