Murray State University
Conditional protein splicing in an essential DNA helicase from the deep sea hydrothermal archaeon Thermococcus kodakarensis
Grade Level at Time of Presentation
Junior
Major
Biology/Pre-Dental
Minor
Chemistry
Institution 23-24
Murray State University
KY House District #
5
KY Senate District #
1
Faculty Advisor/ Mentor
Christopher Lennon
Department
Biology Department
Abstract
Intervening proteins (inteins) are translated within host proteins and removed through a self-catalyzed protein splicing reaction. As mobile genetic elements, inteins are distributed widely in prokaryotes, found within half of archaea and a quarter of bacteria. Moreover, inteins cluster to specific types of genes, often those involved in DNA replication, recombination, and repair. While traditionally assumed to be molecular parasites, work over the last decade has demonstrated that some inteins function as adaptive post-translational regulatory elements, whereby splicing is responsive to environmental conditions. Thermococcus kodakarensis is a microorganism that lives near deep sea hydrothermal vents and grows optimally at 85°C. T. kodakarensis contains fifteen inteins in total and houses two of these inteins within the helicase MCM, a protein essential for DNA replication. In this work, we show that these two MCM inteins, both of which are translated within the same protein, splice at highly-variable rates. One of these inteins, located within the active site of MCM ATPase, requires elevated temperature to induce activity, an environmental condition acutely relevant to T. kodakarensis. Our results provide further support for the model that some inteins have been repurposed by evolution, or “exapted”, from parasite to beneficial regulatory element.
Conditional protein splicing in an essential DNA helicase from the deep sea hydrothermal archaeon Thermococcus kodakarensis
Intervening proteins (inteins) are translated within host proteins and removed through a self-catalyzed protein splicing reaction. As mobile genetic elements, inteins are distributed widely in prokaryotes, found within half of archaea and a quarter of bacteria. Moreover, inteins cluster to specific types of genes, often those involved in DNA replication, recombination, and repair. While traditionally assumed to be molecular parasites, work over the last decade has demonstrated that some inteins function as adaptive post-translational regulatory elements, whereby splicing is responsive to environmental conditions. Thermococcus kodakarensis is a microorganism that lives near deep sea hydrothermal vents and grows optimally at 85°C. T. kodakarensis contains fifteen inteins in total and houses two of these inteins within the helicase MCM, a protein essential for DNA replication. In this work, we show that these two MCM inteins, both of which are translated within the same protein, splice at highly-variable rates. One of these inteins, located within the active site of MCM ATPase, requires elevated temperature to induce activity, an environmental condition acutely relevant to T. kodakarensis. Our results provide further support for the model that some inteins have been repurposed by evolution, or “exapted”, from parasite to beneficial regulatory element.