title: Presence of a motif conserved between Helicobacter pylori TNF-alpha inducing protein (Tipalpha) and penicillin-binding proteins.
abstract: Here we report a primary structure conserved between Helicobacter pylori (H. pylori)-tumor necrosis factor-alpha inducing protein (Tipalpha) and bacterial penicillin-binding proteins. H. pylori is a Gram-negative bacterium which plays a key part in carcinogenesis in the human stomach. We previously reported that Tipalpha has a carcinogenic potential as tumor promoter, and that it has no obvious homologue in other species. To investigate the structure-function relationship of Tipalpha and to predict its ancestral protein, we searched among proteins which have weak homology to Tipalpha in their primary structures, using Psi-Blast, and we identified numerous Gram-positive bacterial penicillin-binding proteins as weakly homologous to Tipalpha. Among these, several unique amino acids are conserved and form a motif-like structure. Phylogenic tree analysis indicated that Tipalpha is closer to the penicillin-binding proteins of Gram-positive bacteria, based on their primary structures, than to H. pylori. This finding suggests that Tipalpha and penicillin-binding proteins are derived from a common ancestral protein, and that Tipalpha gene may be transferred horizontally from Gram-positive bacteria to H. pylori.
authors.affiliation: Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Japan. kuzuhara@ph.bunri-u.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Kuzuhara
authors.forename: Masami
authors.initials: M
authors.lastname: Suganuma
authors.forename: Hideaki
authors.initials: H
authors.lastname: Tsuge
authors.forename: Hirota
authors.initials: H
authors.lastname: Fujiki
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D017124:Conserved Sequence; D022761:Gene Transfer, Horizontal; D006094:Gram-Positive Bacteria / Q000235:genetics; D016480:Helicobacter pylori / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D046915:Penicillin-Binding Proteins / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D040681:Structural Homology, Protein
chemical_list: D001426:Bacterial Proteins; D046915:Penicillin-Binding Proteins; C505332:Tipalpha protein, Helicobacter pylori