BEGIN:VCALENDAR VERSION:2.0 METHOD:PUBLISH PRODID:-//Missouri State University/Calendar of Events//EN CALSCALE:GREGORIAN X-WR-TIMEZONE:America/Chicago BEGIN:VTIMEZONE TZID:America/Chicago BEGIN:DAYLIGHT TZOFFSETFROM:-0600 TZOFFSETTO:-0500 DTSTART:20070311T020000 RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU TZNAME:CDT END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0500 TZOFFSETTO:-0600 DTSTART:20071104T020000 RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU TZNAME:CST END:STANDARD END:VTIMEZONE BEGIN:VEVENT UID:639c6eb9-6e8b-4cd6-9a32-c95be923a877.228039@calendar.missouristate.edu CREATED:20230419T143231Z LAST-MODIFIED:20230419T143231Z LOCATION:Meyer Library\, Duane G. 101 SUMMARY:Chemistry & Biochemistry Seminar: "Modulating protein conformation al changes and divalent metal binding properties to create safer Cas-base d genome tools" DESCRIPTION:By: Dr. Rakhi Rajan - University of Oklahoma\n\n\nAbstract\n\n \nCRISPR-Cas systems protect bacteria and archaea from foreign genetic el ements based on sequence specific RNA-guided targeting and cleavage of th e intruder genome by signature Cas nucleases. Cas9 and Cas12a are two CRI SPR endonucleases\, comprised of multi-domain enzymes that exhibit intric ate conformational controls to elicit sequence-specific DNA cleavage. Eve n though Cas nucleases have revolutionized biotechnological and gene ther apy applications\, the methodology suffers from the ability of Cas nuclea ses to cleave targets that are not completely complementary to the guide- region of the RNA. To address these off-target effects\, we have focused on identifying the role of a highly-conserved arginine-rich helix present in several Cas nucleases\, called the bridge helix\, in regulating speci ficity of DNA cleavage. Our results identified a novel allosteric control that the bridge helix exerts on the endonucleases sites of Cas9\, which is directed by a loop-to-helical transition in the bridge helix. The mech anism is conserved in Cas12a as well\, establishing that bridge helix var iations can be used to develop high-fidelity Cas protein variants for gen ome applications.\n\n\n\n\n\nAnother aspect of our research is to address promiscuous DNA cleavages by Cas nucleases. We discovered that several C as nucleases possess non-specific DNA cleavage in the absence of a guide- RNA. Our on-going research shows that manipulating the active site of Cas nucleases\, specifically related to divalent metal ion binding\, can rem ove promiscuous DNA cleavage without significantly reducing RNA guided DN A cleavage. We propose that removing off-target and promiscuous DNA cleav ages are crucial in deploying the full potential of Cas nucleases in gene therapy and other genome applications. Our combinatorial approach includ ing protein engineering\, biochemistry\, kinetic modeling\, and molecular dynamics simulations provide translatable approaches to study Cas nuclea ses.\n\n\n\n\n\nThe talk will also include information about graduate stu dies in the Department of Chemistry and Biochemistry at the University of Oklahoma. X-ALT-DESC;FMTTYPE=text/html:<html><head><title></title></head><body><p>By : Dr. Rakhi Rajan - University of Oklahoma</p>\n<p>Abstract</p>\n<p>CRISP R-Cas systems protect bacteria and archaea from foreign genetic elements based on sequence specific RNA-guided targeting and cleavage of the intru der genome by signature Cas nucleases. Cas9 and Cas12a are two CRISPR end onucleases\, comprised of multi-domain enzymes that exhibit intricate con formational controls to elicit sequence-specific DNA cleavage. Even thoug h Cas nucleases have revolutionized biotechnological and gene therapy app lications\, the methodology suffers from the ability of Cas nucleases to cleave targets that are not completely complementary to the guide-region of the RNA. To address these off-target effects\, we have focused on iden tifying the role of a highly-conserved arginine-rich helix present in sev eral Cas nucleases\, called the bridge helix\, in regulating specificity of DNA cleavage. Our results identified a novel allosteric control that t he bridge helix exerts on the endonucleases sites of Cas9\, which is dire cted by a loop-to-helical transition in the bridge helix. The mechanism i s conserved in Cas12a as well\, establishing that bridge helix variations can be used to develop high-fidelity Cas protein variants for genome app lications.</p>\n<p></p>\n<p>Another aspect of our research is to address promiscuous DNA cleavages by Cas nucleases. We discovered that several Ca s nucleases possess non-specific DNA cleavage in the absence of a guide-R NA. Our on-going research shows that manipulating the active site of Cas nucleases\, specifically related to divalent metal ion binding\, can remo ve promiscuous DNA cleavage without significantly reducing RNA guided DNA cleavage. We propose that removing off-target and promiscuous DNA cleava ges are crucial in deploying the full potential of Cas nucleases in gene therapy and other genome applications. Our combinatorial approach includi ng protein engineering\, biochemistry\, kinetic modeling\, and molecular dynamics simulations provide translatable approaches to study Cas nucleas es.</p>\n<p></p>\n<p>The talk will also include information about graduat e studies in the Department of Chemistry and Biochemistry at the Universi ty of Oklahoma.</p></body></html> DTSTART;TZID=America/Chicago:20230426T153500 DTEND;TZID=America/Chicago:20230426T162500 SEQUENCE:0 URL:https://chemistry.missouristate.edu/Seminars.htm CATEGORIES:Public,Alumni,Current Students,Faculty,Future Students,Staff END:VEVENT END:VCALENDAR