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Full-Text Articles in Life Sciences

Determination Of The Structure, Function, And Mechanism Of Type Iv Crispr-Cas Prokaryotic Defense Systems, Hannah Nicole Taylor Aug 2021

Determination Of The Structure, Function, And Mechanism Of Type Iv Crispr-Cas Prokaryotic Defense Systems, Hannah Nicole Taylor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bacteria are under constant threat of invasion by bacteriophage (viruses which infect bacteria). To prevent bacteriophage from entering and overtaking the bacteria, bacteria utilize defense systems to identify and destroy foreign elements. One method of defense is called CRISPR-Cas (Clustered Regularly Interspaced Short Palindromic Repeats – CRISPR-Associated). Many different bacteria and most archaea use CRISPR-Cas systems. There are many diverse types of CRISPR-Cas systems, each of which provides defense in a slightly different way. One such CRISPR-Cas type is called type IV. The type IV CRISPR-Cas system is poorly understood and there are very few studies published on type IV …


Transition State Interactions In A Promiscuous Enzyme: Sulfate And Phosphate Monoester Hydrolysis By Pseudomonas Aeruginosa Arylsulfatase, Bert Van Loo, Ryan Berry, Usa Boonyuen, Mark F. Mohamed, Marko Golicnik, Alvan C. Hengge, Florian Hollfelder Feb 2019

Transition State Interactions In A Promiscuous Enzyme: Sulfate And Phosphate Monoester Hydrolysis By Pseudomonas Aeruginosa Arylsulfatase, Bert Van Loo, Ryan Berry, Usa Boonyuen, Mark F. Mohamed, Marko Golicnik, Alvan C. Hengge, Florian Hollfelder

Chemistry and Biochemistry Faculty Publications

Pseudomonas aeruginosa arylsulfatase (PAS) hydrolyses sulfate and, promiscuously, phosphate monoesters. Enzyme-catalyzed sulfate transfer is crucial to a wide variety of biological processes, but detailed studies of the mechanistic contributions to its catalysis are lacking. We present linear free energy relationships (LFERs) and kinetic isotope effects (KIEs) of PAS and active site mutants that suggest a key role for leaving group (LG) stabilization. In LFERs PASWT has a much less negative Brønsted coefficient (ßleaving group obs-Enz=-0.33) than the uncatalyzed reaction (ßleaving group obs=-1.81). This situation is diminished when cationic active site groups are exchanged for alanine. …


Saponin Content And Some Pod And Blossom Characteristics Of Alfalfa As Related To Seed Infestation By The Alfalfa Seed Chalcid, Ronald D. Morse May 1966

Saponin Content And Some Pod And Blossom Characteristics Of Alfalfa As Related To Seed Infestation By The Alfalfa Seed Chalcid, Ronald D. Morse

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The alfalfa seed chalcid, Bruchophagus ruddi Guss., is a jet-black hymenopteran wasp. The destructive nature of this pest has been recognized since the latter part of the nineteenth century. Every year thousands of acres of alfalfa seed are destroyed, with infestation reaching as high as 8 5 percent in some areas. In Utah the chalcid annually ruins from 5 to 25 percent of the alfalfa seed. Much of this damage goes unnoticed, as infested seed is commonly blown out in the trash during harvesting and cleaning operations . The extent of damage is not restricted to the United States. Wherever …