A new type of crystal structure of abc transporter LptB2FG membrane protein complex.

On April 10, Nature Structural and Molecular Biology published online a research paper by Huang Yihua, a researcher at the Institute of Biophysics of the Chinese Academy of Sciences, for lipopolysaccharide by ABC transporter LptB 2FG, analyzing the crystal structure of a new TYPE ABC transporter LptB2FG membrane protein complex, reveals the molecular mechanism of this new ABC transporter lipopolysaccharide (LPS) molecule from the cell membrane.
LPS, also known as endotoxin, forms the outer leaves of the outer membrane of the Glorene-negative bacteria.
lipid polysaccharies are not only the main components of Gloren's negative bacterial outer membrane, but also the main cause of inflammation and the body's natural immune response.
For more than a hundred years, scientists have gained a deep understanding of the synthesis of bacterial polysaccharose in cytosomes, but it wasn't until the early 2000s that Thomas Silhavy, a bacterial geneticist at Princeton University and a member of the American Academy of Sciences, and Daniel Kahne, a biochemist at Harvard University, discovered that trans-membrane transport of bacterial lipid polysaccharose and assembly on the outer membrane were carried out by seven lipid polysaccharine transport proteins (LptA-G).
, LptB, LptF and LptG make up a tectome ABC transporter located on the inner membrane, responsible for pumping LPS from the outer leaves of the inner membrane, and passing the LPS to the LptD-LptE complex located on the outer membrane through LptC and LptA, and finally completing the assembly of the LPS film.
polysaccharose is necessary for the survival of all Glacin-negative bacteria, so the study of the structure and function of lipid polysaccharin molecular transport and assembly-related protein complex can not only deepen the understanding of the mechanism of the formation of Terrain-negative bacterial epidurals, but also provide a solution for the development of new antibiotics to deal with the increasingly serious problem of Gloran-negative bacterial resistance.
Huang Yihua's team in 2014 analyzed the high-resolution crystal structure of 2.4 E of the membrane protein complex LptD-LptE, which is responsible for transporting and assembling lipid polysaccharies on bacterial outer membranes, and initially clarified the molecular structure of how lipid polysaccharid molecules enter the outer membrane of bacteria (Nature, 2014).
years of efforts, the crystal structure of the new ABC transporter LptB2FG complex responsible for pumping LPS from the inner membrane was successfully analyzed.
in the LptB2FG complex, LptF and LptG each contain a trans-membrane domain (TMD), a perurial side beta-jellyroll domain, and an alpha-helix that interacts with LptB.
the transfilm domains of LptF and LptG on the inner membrane form a large extroduct open "V" groove, structural analysis and functional experiments initially indicate that LPS may come into contact with the transfilm domain of LptF and LptG. The surface enters the "V" groove and, on the basis of the energy provided by the LptB binding and hydrolysis ATP, the LPS is transferred to the beta-jellyroll domain by image change, and the pumping process of LPS from the inner membrane is completed.
this study, through the analysis of the structure and function of the LptB2FG complex, reveals the molecular structure of this new ABC transporter liposuction polysaccharoid molecule from the inner membrane and defines LptB2FG as a class of Type III ABC exporter, distinguishing it from Type I and Type II ABC exporter.
Huang Yihuawei article communication author, Huang Yihua Group Ph.D. student Luo Qingshan as the first author of the article, biophysical institute "membrane protein team" Zhang New Deal Task Force, Shanghai National Protein Science Center Li Model Group and Nanjing University of Technology Chemical Engineering College Zhou Min Group also participated in the study.
research has been supported by the National Science Fund for Distinguished Young People, the Ministry of Science and Technology's major research and development program, and the Chinese Academy of Sciences' Strategic Pilot Science and Technology Special (Category B).
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