title: Isolation of a gene family that encodes the porin-like proteins from the human parasitic nematode Trichuris trichiura.
abstract: The major E/S protein of Trichuris trichiura, the human whipworm, is a highly immunogenic 47-kDa protein that has a pore forming activity that is thought to be essential for the attachment of the worm to host mucosal epithelium. By gene analysis, we have demonstrated that this protein belongs to a multigene family, and we have obtained genomic and cDNA information for two of these genes. The encoded proteins are composed of tandem arrays of alternating 50- and 51-amino-acid domains within which the positioning of the cysteine residues is highly conserved. This structure resembles that of four disulphide core domain proteins, such as secretory leucocyte proteinase-1 (SLP-1), but the Trichuris protein family differs in being composed of multiple domains of this type (nine in TT50, 17 in TT95). An analysis of the relationship between the domains, and a comparison of the fine arrangement of the genes, suggests that TT95 has arisen relatively recently following duplication of the TT50 gene, which itself arose by duplication of a SLP-1-like ancestor.
authors: Wellcome Trust Centre for the Epidemiology of Infectious Disease, University of Oxford, Oxford OX1 3PS, UK. guy.barker@zoology.oxford.ac.uk
authors: G C
authors: GC
authors: Barker
authors: D A
authors: DA
authors: Bundy
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D004220:Disulfides / Q000737:chemistry; D019143:Evolution, Molecular; D005091:Exons / Q000235:genetics; D017238:Genes, Helminth; D015801:Helminth Proteins; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D010802:Phylogeny; D018272:Porins / Q000737:chemistry / Q000235:genetics*; D021382:Protein Sorting Signals / Q000235:genetics; D014258:Trichuris / Q000235:genetics* / Q000472:pathogenicity
chemical_list: D004220:Disulfides; D015801:Helminth Proteins; D018272:Porins; D021382:Protein Sorting Signals; C118812:TT95 protein, Trichuris trichiura