Article
Biochemistry & Molecular Biology
Alessandra M. Martorana, Elisabete C. C. M. Moura, Paola Sperandeo, Flavia Di Vincenzo, Xiaofei Liang, Eric Toone, Pei Zhou, Alessandra Polissi
Summary: Lipopolysaccharide (LPS) in the outer membrane of Gram-negative bacteria plays a crucial role in protecting the cell and LPS transport system is essential for maintaining the barrier function. Defects in LPS transport can lead to modifications in the cell envelope and compromise the permeability barrier properties.
FRONTIERS IN MOLECULAR BIOSCIENCES
(2021)
Article
Biochemistry & Molecular Biology
Andrew Wilson, Natividad Ruiz
Summary: LPS plays a critical role in the outer membrane of Gram-negative bacteria. The transmembrane helix of LptC is involved in maintaining LptC levels and coupling the activities of LptB and LptF/LptG.
MOLECULAR MICROBIOLOGY
(2022)
Article
Microbiology
Federica. A. A. Falchi, Rebecca. J. J. Taylor, Sebastian. J. J. Rowe, Elisabete C. C. M. Moura, Tiago Baeta, Cedric Laguri, Jean-Pierre Simorre, Daniel. E. E. Kahne, Alessandra Polissi, Paola Sperandeo
Summary: The presence of external LPS layer in Gram-negative bacteria makes them resistant to antibiotics. LPS is transported to the cell surface by a molecular machine made of seven essential proteins. LptC plays a role in coordinating energy production and LPS transport in the ABC transporter LptB(2)FGC.
Article
Multidisciplinary Sciences
Wen-Yi Low, Shuhua Thong, Shu-Sin Chng
Summary: The study utilized an in vitro lipid transfer assay to reveal the mechanism of lipid transfer between MlaC and MlaFEDB, showing that MlaC transfers PLs to the IM transporter in an MlaD-dependent manner and can be enhanced through ATP hydrolysis. Additionally, MlaD is crucial for modulating the coupling between ATP hydrolysis and retrograde PL transfer.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Biochemistry & Molecular Biology
Kathryn M. Schultz, John R. Schneider, Matthew A. Fischer, Nicholas P. Cina, Molly O. Riegert, Dara W. Frank, Candice S. Klug
Summary: The outer leaflet of the bacteria's outer membrane is composed of lipopolysaccharide (LPS) and is transported by the LPS transport system. LptA protein is crucial for cell viability and the transportation of LPS. Through a high-throughput screen, it was found that LptA is highly tolerant to alanine substitutions and no single residue is responsible for LPS binding.
Review
Biochemistry & Molecular Biology
Randi L. Guest, Steven T. Rutherford, Thomas J. Silhavy
Summary: The outer membrane of Gram-negative bacteria is a crucial component that provides cell rigidity and acts as a permeability barrier. The regulation of lipid A biogenesis is essential in maintaining asymmetrical bilayer structure of the membrane. Disruption of this process can lead to new targets for antibiotics to combat resistance mechanisms.
TRENDS IN MICROBIOLOGY
(2021)
Article
Cell Biology
Yijie Dong, Honghong Dong, Zengwei Feng, Xing Wang, Qing Yao, Honghui Zhu
Summary: This study demonstrates that obstruction of siderophore transport decreases the predation ability of myxobacteria, possibly by regulating the expression of lytic enzyme genes. This research is of great importance for understanding the ecological aspects of bacterial competition.
Article
Multidisciplinary Sciences
Kamil Nosol, Rose Bang-Sorensen, Rossitza N. Irobalieva, Satchal K. Erramilli, Bruno Stieger, Anthony A. Kossiakoff, Kaspar P. Locher
Summary: ABCB4 is expressed in hepatocytes and plays a key role in translocating phosphatidylcholine into bile canaliculi. Cryogenic electron microscopy structures of ABCB4 reveal its specificity for phosphatidylcholine and the essential role of key residues in this process. These findings provide a structural basis for understanding bile generation and its sensitivity to azole drugs.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Biochemistry & Molecular Biology
Ashlee M. Plummer-Medeiros, Alan T. Culbertson, Claudio L. Morales-Perez, Maofu Liao
Summary: The human ATP-binding cassette transporter ABCA1 plays a critical role in lipid homeostasis. Deleterious mutations of ABCA1 lead to sterol accumulation and are associated with various diseases. The mechanism by which ABCA1 drives lipid movement is poorly understood. In this study, a stable expression system was established for both a human cell-based sterol export assay and protein purification. The produced ABCA1 protein showed activity in sterol export and displayed enhanced ATPase activity. Cryo-EM study revealed multiple distinct conformations and a previously unknown structure of nanodisc-embedded ABCA1. This platform provides important mechanistic and structural insights for investigating ABCA1 modulators.
JOURNAL OF MOLECULAR BIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Kristin Oepen, Hueseyin Ozbek, Anja Schueffler, Johannes C. Liermann, Eckhard Thines, Dirk Schneider
Summary: ABC transporters, found in all kingdoms of life, transport substrates against concentration gradients across membranes. Some natural substances have been found to inhibit the activity of ABC transporters, showing potential implications for the regulation of these proteins in biological membranes.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Multidisciplinary Sciences
Chancievan Thangaratnarajah, Jan Rheinberger, Cristina Paulino, Dirk J. Slotboom
Summary: Energy-coupling factor (ECF)-type transporters are small, asymmetric membrane protein complexes that import micronutrients into bacterial cells. Recent research suggests that during the transport process, protein-induced membrane deformations facilitate the toppling of the S component.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Microbiology
Natividad Ruiz, Rebecca M. Davis, Sujeet Kumar
Summary: The process of transporting phospholipids to the outer membrane in Gram-negative bacteria, an essential step in envelope biogenesis, remains unclear. Through studying the AsmA-like clan in Escherichia coli, it was found that YhdP and its homologs TamB and YdbH play important roles in maintaining lipid homeostasis and growth in the outer membrane. These proteins are proposed to be the long-sought-after phospholipid transporters essential for outer membrane biogenesis.
Review
Biochemistry & Molecular Biology
Florestan L. Bilsing, Manuel T. Anlauf, Eymen Hachani, Sakshi Khosa, Lutz Schmitt
Summary: Members of the superfamily of ABC transporters are present in all domains of life. Most of these transporters function as independent entities, utilizing ATP to actively transport substrates across membranes. However, some ABC transporters are part of larger protein complexes known as nanomachineries, which facilitate the vectorial transport of substrates. In this article, we focus on four bacterial examples of such nanomachineries and provide a summary of existing data, as well as a structure-function analysis that highlights the mechanistic coupling of ATP hydrolysis to substrate translocation.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Review
Biochemistry & Molecular Biology
James S. Davies, Michael J. Currie, Joshua D. Wright, Michael C. Newton-Vesty, Rachel A. North, Peter D. Mace, Jane R. Allison, Renwick C. J. Dobson
Summary: Multicomponent transporters in bacteria are crucial for the uptake of nutrients, with implications for colonization and pathogenicity in humans. Current research focuses on the membrane interactions and the roles of lipids and higher oligomers in these complex systems.
FRONTIERS IN MOLECULAR BIOSCIENCES
(2021)
Article
Chemistry, Multidisciplinary
Tim Diederichs, Robert Tampe
Summary: Cellular life relies on transport and communication across membranes, making membrane proteins prime drug targets. Researchers have successfully reconstituted membrane assemblies using giant liposomes, demonstrating the unidirectional transport of substrates by nanomachineries. This approach enables the construction of delicate artificial cell-like systems for real-time tracking of substrate transport.
Article
Chemistry, Multidisciplinary
Chiara Gargioni, Mykola Borzenkov, Laura D'Alfonso, Paola Sperandeo, Alessandra Polissi, Lucia Cucca, Giacomo Dacarro, Pietro Grisoli, Piersandro Pallavicini, Agnese D'Agostino, Angelo Taglietti
Article
Microbiology
Elisabete C. C. M. Moura, Tiago Baeta, Alessandra Romanelli, Cedric Laguri, Alessandra M. Martorana, Emanuele Erba, Jean-Pierre Simorre, Paola Sperandeo, Alessandra Polissi
FRONTIERS IN MICROBIOLOGY
(2020)
Article
Chemistry, Multidisciplinary
Mykola Borzenkov, Giuseppe Chirico, Piersandro Pallavicini, Paola Sperandeo, Alessandra Polissi, Giacomo Dacarro, Lavinia Doveri, Maddalena Collini, Laura Sironi, Margaux Bouzin, Laura D'Alfonso
Article
Biochemistry & Molecular Biology
Carlos K. Gurnani Serrano, Matthias Winkle, Alessandra M. Martorana, Jacob Biboy, Niccolo More, Patrick Moynihan, Manuel Banzhaf, Waldemar Vollmer, Alessandra Polissi
Summary: In this study, it was shown that the morphological defects and lysis associated with a ldtF mutant with impaired LPS transport can be alleviated by the loss of the OM-anchored lipoprotein ActS. ActS was found to be an inactive member of LytM-type peptidoglycan endopeptidases, capable of activating several periplasmic peptidoglycan amidases. Additionally, ActS was shown to preferentially activate AmiC and its function is linked to cell envelope stress.
MOLECULAR MICROBIOLOGY
(2021)
Article
Microbiology
Matthias Winkle, Victor M. Hernandez-Rocamora, Karthik Pullela, Emily C. A. Goodall, Alessandra M. Martorana, Joe Gray, Ian R. Henderson, Alessandra Polissi, Waldemar Vollmer
Summary: Research on E. coli has revealed that the attachment of Lpp to peptidoglycan in Gram-negative bacteria is a dynamic process, where detachment of Lpp can be beneficial under certain stress conditions. Furthermore, the enzyme DpaA, identified in this study, is present in many Gram-negative bacteria and may have different substrates in these species.
Article
Chemistry, Multidisciplinary
Pietro Grisoli, Lorenzo De Vita, Chiara Milanese, Angelo Taglietti, Yuri Diaz Fernandez, Margaux Bouzin, Laura D'Alfonso, Laura Sironi, Silvia Rossi, Barbara Vigani, Paola Sperandeo, Alessandra Polissi, Piersandro Pallavicini
Summary: This study successfully prepared PVA films embedded with silver nanoparticles, NIR-absorbing photothermal gold nanostars, or a combination of both. The slow but prolonged release of silver ions from the films exhibited strong antimicrobial effects against bacteria, while the films also showed rapid hyperthermal bactericidal action upon NIR laser irradiation. The biocompatibility of all films was confirmed, with negligible impact on human fibroblast viability observed.
Article
Biochemistry & Molecular Biology
Alessandra M. Martorana, Elisabete C. C. M. Moura, Paola Sperandeo, Flavia Di Vincenzo, Xiaofei Liang, Eric Toone, Pei Zhou, Alessandra Polissi
Summary: Lipopolysaccharide (LPS) in the outer membrane of Gram-negative bacteria plays a crucial role in protecting the cell and LPS transport system is essential for maintaining the barrier function. Defects in LPS transport can lead to modifications in the cell envelope and compromise the permeability barrier properties.
FRONTIERS IN MOLECULAR BIOSCIENCES
(2021)
Article
Biochemistry & Molecular Biology
Sheetal Sinha, Vidhya Bharathi Dhanabal, Paola Sperandeo, Alessandra Polissi, Surajit Bhattacharjya
Summary: Currently, the options for antibiotic treatment of infections caused by drug resistant Gram-negative pathogens are limited. Hence, researchers have explored the use of insect-derived antimicrobial peptide Thanatin as an effective antibiotic against Gram-negative bacteria. This study investigates the structure-activity correlation of Thanatin and its analogs, and identifies the M21F analog as having superior antibacterial activity and higher affinity binding to LPS and LptA(m) compared to Thanatin. The findings provide a framework for the rational design of potent antimicrobial peptides based on Thanatin for the treatment of drug resistant Gram-negative bacteria.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES
(2022)
Article
Chemistry, Physical
Ermelinda Falletta, Claudia Letizia Bianchi, Franca Morazzoni, Alessandra Polissi, Flavia Di Vincenzo, Ignazio Renato Bellobono
Summary: The increased air pollution has raised global concerns about its impact on the environment and human health. This study investigated the photocatalytic degradation of nitrogen oxides (NOx) and the inactivation of Escherichia coli using TiO2/WO3 composites. The results showed that the performance of the composites in NOx degradation under visible light was influenced by the WO3 content, while E. coli could not be degraded under visible light irradiation of the composites.
Article
Nanoscience & Nanotechnology
Paola Sperandeo, Fabrizio Bosco, Francesca Clerici, Alessandra Polissi, Maria Luisa Gelmi, Alessandra Romanelli
ACS APPLIED BIO MATERIALS
(2020)
Article
Cell Biology
Sara Motta, Davide Vecchietti, Alessandra M. Martorana, Pietro Brunetti, Giovanni Bertoni, Alessandra Polissi, Pierluigi Mauri, Dario Di Silvestre
