Zyrill Dela Cruz, University of Hawai'i Hilo
Zyrill is an upcoming junior majoring in chemistry at the University of Hawai'i at Hilo. In Dr. Kim's lab she is focusing on the structure and understanding of the mechanism of the human form of endonuclease SLXI and endonuclease SLX4. SLX41 by itself is inactive until it binds to the C-terminal region of SLX4. When the SLX1-SLX4 complex is formed, it is able to repair breaks in double-stranded DNA. Those broken double-stranded DNA can be caused by mechanical stress, chemical changes, metabolic reactions, chemotherapeutic drugs, and the process of meiosis. They go unrepaired, it can lead to gene deletion and chromosomal mutations. The SLX1-SLX4 complex is able to repair these breaks in DNA by cleaving near the branch point of branched DNA substrates. However, the mechanism of this actions is unknown. To learn more about this process, her goal is to purify SLX1 and SLX4 and have it be crystallized. The SLX1 and SLX4 complex is first expressed in Escherichia coli and followed by protein purification through affinity chromatography. Variables like affinity tags and pH are manipulated to find optimal condition at which SLX1 and SLX4 will purify. IF successfully purified, the endonucleases will be crystallized, and the results will be assessed to determine the structure and mechanism of action of the two proteins. This information will aid in further drug discovery.