Abstract 1290 The Homing Endonuclease Activity of Inteins From Two Extreme Thermophiles

Inteins are intervening amino acid sequences that are spontaneously removed from proteins during protein splicing. Many interns, such as the intein within the DNA polymerase ll protein, contain a homing endonuclease domain. Homing endonucleases function to cleave molecules of double-stranded DNA. The homing endonucleases we are interested in are within the inteins of the polymerase Ⅱ gene of two thermophiles, Thermococcus barophilus and Thermococcus kodakarensis. The homing endonucleases of these inteins are heat stable, and there is a correlation between higher temperature and increased enzyme activity. DNA cleavage occurs optimally at 50°C for both enzymes, with T. kodakarensis's intein requiring ten-fold less enzyme to reach the same unit of activity. Additionally, we hypothesize that the homing endonuclease within T.kodakanrensis's inteins may have a different response to pressure than that from T. barophilus due to the organism's growth at high pressure. We thank the National Institutes of Health, NIGMS (Grant 1R15GM132817-01) for supporting our research.