Date of Award
Master of Science
The use of antibiotics has undoubtedly been a boon for humanity in combating infections and microbial threats. However, their widespread utilization has contributed to the emergence and spread of antibiotic resistance, which now poses a significant public health challenge. Streptomyces bacterium, produce diverse secondary metabolites with antibacterial, antifungal, antiviral, antitumoral, and immunosuppressant activities. Among these compounds is echinomycin, a nonribosomal peptide antibiotic synthesized by Streptomyces lasalocidi, which inhibits DNA replication and transcription by intercalating the DNA duplex at CpG steps. A gene called ecm16 was identified in the echinomycin biosynthetic gene cluster, which provides echinomycin self-resistance. Ecm16 recognizes DNA duplexes that contain echinomycin, and neutralizes its toxicity through a yet undetermined mechanism. To shed light on this process, we are determining the crystal structure of Ecm16 containing ATP. We introduced strategic mutations in the nucleotide binding site of Ecm16 to prevent ATP hydrolysis. We have successfully cloned, expressed, and purified the recombinant Ecm16 E399Q,E708Q double mutant protein. We have solved the structure of this protein using X-ray Crystallography at a resolution of 2.07 Ã?. However, our crystal structure contained ADP instead of the expected ATP. We propose and alternative experimental strategies for structure determination of ATP-containing Ecm16.
Recieved from ProQuest
Guillama, Gileydis, "X-Ray Crystal Structure Of E399q,e708q Ecm16 Double Mutant" (2023). Open Access Theses & Dissertations. 3911.