Biomaterial Database

CryoEM structure of the outer membrane secretin channel pIV from the f1 filamentous bacteriophage. 2021

Rebecca Conners, and Mathew McLaren, and Urszula Łapińska, and Kelly Sanders, and M Rhia L Stone, and Mark A T Blaskovich, and Stefano Pagliara, and Bertram Daum, and Jasna Rakonjac, and Vicki A M Gold

Living Systems Institute, University of Exeter, Exeter, UK.

The Ff family of filamentous bacteriophages infect gram-negative bacteria, but do not cause lysis of their host cell. Instead, new virions are extruded via the phage-encoded pIV protein, which has homology with bacterial secretins. Here, we determine the structure of pIV from the f1 filamentous bacteriophage at 2.7 Å resolution by cryo-electron microscopy, the first near-atomic structure of a phage secretin. Fifteen f1 pIV subunits assemble to form a gated channel in the bacterial outer membrane, with associated soluble domains projecting into the periplasm. We model channel opening and propose a mechanism for phage egress. By single-cell microfluidics experiments, we demonstrate the potential for secretins such as pIV to be used as adjuvants to increase the uptake and efficacy of antibiotics in bacteria. Finally, we compare the f1 pIV structure to its homologues to reveal similarities and differences between phage and bacterial secretins.

UI	MeSH Term	Description	Entries
D000072416	Protein Structural Elements	Distinguishing three-dimensional structures characteristically formed by homologous protein sequences.	Protein Structural Units,Protein Structure Elements,Element, Protein Structural,Elements, Protein Structural,Protein Structural Element,Protein Structural Unit,Protein Structure Element,Structural Element, Protein,Structural Elements, Protein,Structural Unit, Protein,Structural Units, Protein,Structure Element, Protein,Structure Elements, Protein
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D001692	Biological Transport	The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.	Transport, Biological,Biologic Transport,Transport, Biologic
D012633	Secretin	A peptide hormone of about 27 amino acids from the duodenal mucosa that activates pancreatic secretion and lowers the blood sugar level. (USAN and the USP Dictionary of Drug Names, 1994, p597)	Secrepan,Secretin Citrate, Pig,Secretin Maleate, Pig,Secretin Pentacetate, Pig,Secretin Sulfate, Pig,Secretin, Pig,Secretin-KABI,Pig Secretin,Pig Secretin Citrate,Pig Secretin Maleate,Pig Secretin Pentacetate,Pig Secretin Sulfate,Secretin KABI,SecretinKABI
D016415	Sequence Alignment	The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.	Sequence Homology Determination,Determination, Sequence Homology,Alignment, Sequence,Alignments, Sequence,Determinations, Sequence Homology,Sequence Alignments,Sequence Homology Determinations
D017361	Viral Nonstructural Proteins	Proteins encoded by a VIRAL GENOME that are not structural components of VIRUS PARTICLES. Some of these proteins may play roles within the infected cell during VIRUS REPLICATION or act in regulation of virus replication or VIRUS ASSEMBLY.	Nonstructural Proteins, Viral,NS Proteins, Viral,Viral NS Proteins,Viral Non-Structural Proteins,Viral Nonstructural Protein,Viral Nonstructural Proteins NS1,Viral Nonstructural Proteins NS2,Nonstructural Protein, Viral,Viral Non Structural Proteins
D017912	Inovirus	A genus of filamentous bacteriophages of the family INOVIRIDAE. Organisms of this genus infect enterobacteria, PSEUDOMONAS; VIBRIO; and XANTHOMONAS.	Bacteriophages, Filamentous,Filamentous Bacteriophages,Bacteriophage, Filamentous,Filamentous Bacteriophage,Inoviruses
D020285	Cryoelectron Microscopy	Electron microscopy involving rapid freezing of the samples. The imaging of frozen-hydrated molecules and organelles permits the best possible resolution closest to the living state, free of chemical fixatives or stains.	Electron Cryomicroscopy,Cryo-electron Microscopy,Cryo electron Microscopy,Cryo-electron Microscopies,Cryoelectron Microscopies,Cryomicroscopies, Electron,Cryomicroscopy, Electron,Electron Cryomicroscopies,Microscopies, Cryo-electron,Microscopies, Cryoelectron,Microscopy, Cryo-electron,Microscopy, Cryoelectron