Cloning and expression of the filamentous bacteriophage Pf1 major coat protein gene in Escherichia coli. Membrane protein processing and virus assembly.

摘要: Abstract A restriction fragment carrying the major coat protein gene (gene VIII) was excised from replicative form (RF) DNA of class II filamentous bacteriophage Pf1, which infects Pseudomonas aeruginosa . This cloned into expression plasmid pKK223-3, where it came under control tac promoter. In transformed Escherichia coli JM101 cells, in presence inducer isopropyl-β- d -thiogalactoside, Pf1 strongly expressed. The displays same pattern negatively charged N-terminal region, hydrophobic middle region and positively C-terminal as that its counterpart I fd, E. , but otherwise two proteins have no sequence homology. However, procoat found to undergo processing insertion cell inner membrane, like fd counterpart, demonstrating this part assembly process is for these different bacteriophages. complete transcriptional unit, incorporating promoter rrnB transcription terminators flanking gene, intergenic space R252, an carries amber mutation own gene. again well expressed infected cells chimeric had growth properties identical those parent R252 on suppressor nonsuppressor strains evidently cannot be recognized by complex at or either point initiation during elongation process.