Unveiling the architectures of five bacterial biomolecular machines

dc.contributor.advisorKeatinge-Clay, Adrian Tristanen
dc.contributor.committeeMemberHoffman, David Wen
dc.contributor.committeeMemberWhitman, Christian Pen
dc.contributor.committeeMemberAppling, Dean Ren
dc.contributor.committeeMemberIverson, Brent Len
dc.contributor.committeeMemberHackert, Marvin Len
dc.creatorFage, Christopher Daneen
dc.date.accessioned2015-09-10T12:58:21Zen
dc.date.accessioned2018-01-22T22:28:05Z
dc.date.available2018-01-22T22:28:05Z
dc.date.issued2014-08en
dc.date.submittedAugust 2014en
dc.date.updated2015-09-10T12:58:21Zen
dc.descriptiontexten
dc.description.abstractNatural products represent an incredibly diverse set of chemical structures and activities. Given this fathomless, ever-evolving diversity, a reasonable approach to designing new molecules entails taking a closer look at the biochemistry that Nature has crafted over billions of years on Earth. In particular, much can be learned by unveiling the architectures of proteins, life’s molecular machines, through methods like X-ray crystallography. Acquiring the blueprints of an enzyme brings us closer to understanding the mechanism by which the enzyme transforms a simple substrate it into a complex product with biological function, and inspires us to engineer such systems to our own ends. With a focus on macromolecular structural characterization, this document elaborates on five Gram-negative bacterial biosynthetic enzymes from two categories: Cell-surface modifiers and polyketide synthases. Among the first category are the glycyl carrier protein AlmF and its ligase AlmE of Vibrio cholerae and the phosphoethanolamine transferase EptC of Campylobacter jejuni. These proteins are responsible for decorating cell-surface molecules (e.g., lipid A) of pathogenic bacteria with small functional groups to promote antibiotic resistance, motility, and host colonization. AlmE and EptC represent potential drug targets and their structures lay the groundwork for the design of therapeutics against food-borne illnesses. Included in the second category are the [4+2]-cyclase SpnF and two ketoreductase-linked dimerization elements, each from the spinosyn biosynthetic pathway in Saccharopolyspora spinosa. The former catalyzes a putative Diels-Alder reaction to form a tricyclic precursor of the insecticide spinosad, while the latter two organize ketoreductase domains within modules of a polyketide synthase. The second category also includes Ralstonia eutropha β-ketoacyl thiolase B, a substrate-permissive enzyme that can make or break carbon-carbon bonds with assistance from Coenzyme A or an analogous thiol. Each of these proteins exhibit intriguing structural features or catalyze reactions that show promise for biochemical engineering.en
dc.description.departmentBiochemistryen
dc.format.mimetypeapplication/pdfen
dc.identifier.urihttp://hdl.handle.net/2152/31282en
dc.language.isoenen
dc.subjectX-ray crystallographyen
dc.subjectStructural biologyen
dc.subjectBiosynthesisen
dc.subjectEnzymeen
dc.subjectAlmEen
dc.subjectAdenylation domainen
dc.subjectEptCen
dc.subjectPhospho-form transferaseen
dc.subjectSpnDEen
dc.subjectDimerization elementen
dc.subjectSpnFen
dc.subjectCyclaseen
dc.subjectBktBen
dc.subjectBeta-ketoacyl thiolaseen
dc.subjectPolyketide synthaseen
dc.titleUnveiling the architectures of five bacterial biomolecular machinesen
dc.typeThesisen

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