On April 9th, 2018, Prof. Ming Zhou visited Institute of Biophysics, CAS and gave a lecture entitled “Elevators in cell membrane: transporters in motion”. The lecture was hosted by Prof.Zhenfeng Liu, and was part of the special lecture series named “ShizhangBei Lecture” of Institute of Biophysics.
Professor Ming Zhou started his presentationby mentioningProf.Bei's theory of cell reconstruction.Firstly, he introduced three common types of transporters, namelypassive uniporters、ion-coupled symportersand ABC transporters, and a fourth type named phosphoenolpyruvate:carbohydratephosphotransferase (PTS) system driven by phosphorylation.In bacterial cells, the PTS system mediate the transmembrane transport of carbohydrate molecules by the EIIC components located on the membrane, while the mechanism of conformation changes during the transport of substratesmediated by EIIC protein is to be investigated systematically and in detail.
Professor Ming Zhou's lab has been studying the transport mechanism of EIIC protein by combining structural and functional approaches for many years. In histalk, Prof. Zhou introduced the crystal structure of EIIC protein from Bacillus cereus(bcChbC) which was first reportedby his group.It was found that the protein contained a dimerization domain and a transport domain. There wasa substrate bound in theinward-facing pocketof the transport domain.After that, they have solved the 2.6Åresolution structure of the bcMalT protein that transports maltose in an outward-facing state by using the lipid cubid phase (LCP) method. Both bcMalT and bcChbC are EIIC family proteins with similar folding pattern and topology, but they are trapped in different conformational states.Furthermore, by combining the homology modeling and disulfide crosslinking method, they have captured the inward-facingstructure of bcMalT.By analyzing the outward-facing and inward-facing structures of bcMalT, theyhave found that the transport domainmoves as arigid-body going through a significant conformational change relative to the dimerization domain. The movement includes a 44 °rotation and 9Å longitudinal translation. After that, single molecule fluorescence resonance energy transfer (smFRET) method was applied to detect the different conformations of bcMalT in solution and the resultsare cconsistent with the observation based onthe crystal structures.
Finally, Professor Zhou summarized the works onthe structures and functions of EIIC proteins, and proposed a mechanistic model to account for the transport of carbohydrate molecules across the membrane mediated by the EIIC proteins.Professor Ming Zhou's presentationincludes rich scientific content, stringent logic, clearquestion-driventhinking and diversetechniques.Inspired by his talk, the attendees asked questions actively and discussed with Professor Zhoudeeplyon the scientific topics related to EIIC.During the presentation and discussion, the meetingroom was filled with academic atmosphere.At the end of the report, director RuimingXupresentedtheShizhangBeiLecture souvenir as a gift toProfessor Ming Zhou.
Prof. Ming Zhou was giving the lecture
Prof. Zhenfeng Liu hosted the lecture
Scene of the lecture
Prof. RuimingXu and Prof. Ming Zhou