BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Molecular basis for the transfer of large toxin plasmids in Clostr idium perfringens DTSTART;VALUE=DATE-TIME:20210324T151000Z DTEND;VALUE=DATE-TIME:20210324T153000Z DTSTAMP;VALUE=DATE-TIME:20260714T165152Z UID:indico-contribution-401-6944@events.saip.org.za DESCRIPTION:Speakers: Daouda Traore ()\nThe transfer of large toxin and an tibiotic resistance genes in the pathogenic bacteria *Clostridium perfring ens* is mediated by the *tcp* conjugation locus. Functional genetic analys is of the tcp locus of the paradigm plasmid pCW3 has revealed that its gen e products assemble into a multi-protein complex that distantly resembles a type 4 secretion system (T4SS). \n\nHere\, I will provide a brief summar y of our current understanding of the DNA system.\, knowledge that was bui lt upon a combination of structural biology studies and functional microbi al genetics\n\nhttps://events.saip.org.za/event/213/contributions/6944/ LOCATION:Zoom Conference URL:https://events.saip.org.za/event/213/contributions/6944/ END:VEVENT BEGIN:VEVENT SUMMARY:Structural and functional characterization of the secreted adhesio n EtpA of enterotoxigenic Escherichia coli DTSTART;VALUE=DATE-TIME:20210324T145000Z DTEND;VALUE=DATE-TIME:20210324T151000Z DTSTAMP;VALUE=DATE-TIME:20260714T165152Z UID:indico-contribution-401-6940@events.saip.org.za DESCRIPTION:Speakers: Clifford Manyo Ntui (University of Pretoria)\nOral p resentation\n\nhttps://events.saip.org.za/event/213/contributions/6940/ LOCATION:Zoom Conference URL:https://events.saip.org.za/event/213/contributions/6940/ END:VEVENT BEGIN:VEVENT SUMMARY:Structural and un-structural biology by NMR spectroscopy DTSTART;VALUE=DATE-TIME:20210324T142000Z DTEND;VALUE=DATE-TIME:20210324T145000Z DTSTAMP;VALUE=DATE-TIME:20260714T165152Z UID:indico-contribution-401-6945@events.saip.org.za DESCRIPTION:Speakers: Roberta Pierattelli (CERM\, University of Florence)\ nNuclear Magnetic Resonance (NMR) spectroscopy is an enabling technology c apable to provide information and answers to biological problems that cann ot be obtained by other means. NMR studies\, both in solution and in the s olid-state\, can inform on the structure of a macromolecule in many differ ent environments ranging from buffered solutions to intact cells\, can pro vide insight into dynamic processes\, and allow to monitor biomolecular in teractions that are key to the cellular response to environmental\, develo pmental and growth signals. \nNMR is central to the study of folding\, unf olding and disordered states of proteins because of its capability to defi ne the structures of proteins in solution and to characterize the dynamic properties that are inherent to function. \nAs such\, we will provide some examples of recent applications of NMR spectroscopy carried out at the CE RM/CIRMMP infrastructure\, the Italian centre for NMR spectroscopy of Inst ruct-ERIC.\n\nhttps://events.saip.org.za/event/213/contributions/6945/ LOCATION:Zoom Conference URL:https://events.saip.org.za/event/213/contributions/6945/ END:VEVENT BEGIN:VEVENT SUMMARY:Structural biology using neutrons: introduction and how to get sta rted DTSTART;VALUE=DATE-TIME:20210324T130000Z DTEND;VALUE=DATE-TIME:20210324T134000Z DTSTAMP;VALUE=DATE-TIME:20260714T165152Z UID:indico-contribution-401-6939@events.saip.org.za DESCRIPTION:Speakers: Zoe Fisher (European spallation source ERIC)\nThe me thod of choice for obtaining detailed\, high resolution structural informa tion macromolecules is X-ray crystallography. The magnitude of X-ray scatt ering from the electron cloud around an atomic nucleus is related to the Z number of that element\, i.e.\, the more electrons an atom has\, the bett er it will scatter X-rays. Due to this it is very challenging in theory an d practice to determine the position of H atoms in crystal structures. Neu tron diffraction offers a highly complementary approach in that the neutro ns are scattered from atomic nuclei of all elements to a similar extent. T his means that in practice the nuclear density maps for C\, N\, H (and its isotope Deuterium\, or D)\, and O atoms all appear to a similar extent\, even at medium (~2 Å) resolution. H atoms are very important in biology a s they are involved with everything – including hydrogen bonds\, protein folding\, solvation\, electrostatics\, amino acid side chain charge state \, ligand binding\, and enzyme catalytic mechanisms. To profit from neutro n scattering properties and to be able to “see” these H atoms\, it is crucial to deuterate (i.e. replace all H with isotope D) the materials to be studied. Multiple approaches to biological deuteration will be explaine d as well as the growth of large protein crystals for neutron diffraction. Finally\, some practical aspects of what beamlines are available\, and ho w to get access to neutron scattering facilities will be covered.\n\nhttps ://events.saip.org.za/event/213/contributions/6939/ LOCATION:Zoom Conference URL:https://events.saip.org.za/event/213/contributions/6939/ END:VEVENT BEGIN:VEVENT SUMMARY:Structure of mycobacterial ATP synthase with the TB drug bedaquili ne DTSTART;VALUE=DATE-TIME:20210324T134000Z DTEND;VALUE=DATE-TIME:20210324T142000Z DTSTAMP;VALUE=DATE-TIME:20260714T165152Z UID:indico-contribution-401-6935@events.saip.org.za DESCRIPTION:Speakers: John Rubinstein (The Hospital for Sick Children)\nTu berculosis (TB)\, the world’s leading cause of death by infectious disea se\, is increasingly resistant to current first line antibiotics. The bact erium Mycobacterium tuberculosis that causes TB can survive low-energy con ditions\, which allows infections to remain dormant and decreases their su sceptibility to many antibiotics. Bedaquiline was developed in 2005 from a lead compound identified in a phenotypic screen against M. smegmatis. It can sterilize even latent infections and has become a cornerstone of treat ment for multidrug-resistant and extensively drug-resistant TB. Bedaquilin e targets the mycobacterial ATP synthase\, an essential enzyme in the obli gate aerobic Mycobacterium genus\, but how it binds the intact complex is unknown. We determined structures of M. smegmatis ATP synthase with and wi thout bedaquiline. The drug-free structure suggests how hook-like extensio ns from the alpha subunits prevent the enzyme from running in reverse\, in hibiting ATP hydrolysis and preserving energy in hypoxic conditions. Bedaq uiline binding induces large conformational changes\, creating tight bindi ng pockets at the interface of subunits a and c that explain the drug’s potency as an antibiotic for TB.\n\nhttps://events.saip.org.za/event/213/c ontributions/6935/ LOCATION:Zoom Conference URL:https://events.saip.org.za/event/213/contributions/6935/ END:VEVENT END:VCALENDAR