title: Sequence and transcriptional start site of the Pseudomonas aeruginosa outer membrane porin protein F gene.
abstract: Porin F is one of the major proteins of the outer membrane of Pseudomonas aeruginosa. It forms water-filled pores of variable size. Porin F is a candidate for a vaccine against P. aeruginosa because it antigenically cross-reacts in all serotype strains of the International Antigenic Typing Scheme. We have isolated the gene for porin F from a lambda EMBL3 bacteriophage library by using oligodeoxynucleotide hybridization probes and have determined its nucleotide sequence. Different peptide sequences obtained from isolated porin F confirmed the deduced protein sequence. The mature protein consists of 326 amino acid residues and has a molecular weight of 35,250. The precursor contains an N-terminal signal peptide of 24 amino acid residues. S1 protection and primer extension experiments, together with Northern (RNA) blots, indicate that the mRNA coding for porin F is monocistronic with short untranslated regions of about 58 bases at the 5' end and about 47 bases at the 3' end. The sequences in the -10 and -35 regions upstream of the transcriptional start site are closely related to the Escherichia coli promoter consensus sequences, which explains why the porin F gene is expressed in E. coli under the control of its own promoter. The amino acid sequence of porin F is not homologous to the different E. coli porins OmpF, OmpC, LamB, and PhoE. On the other hand, a highly homologous region of 30 amino acids between the OmpA proteins of different enteric bacteria and porin F of P. aeruginosa was detected. The core region of the homology to E. coli OmpA had 11 of 12 amino acid residues in common.
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D007473:Ion Channels; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D018272:Porins; D011550:Pseudomonas aeruginosa / Q000235:genetics* / Q000276:immunology; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
chemical_list: D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial; D007473:Ion Channels; D018272:Porins