2012- 21st Annual NC State Undergraduate Research Symposium

Session Time : 4/10/12 10:30 AM - 4/10/12 11:45 AM

Content Area : Microbiology

Poster Appointment: , -

Student Presenters :
Christina Alice Grace McChesney Biology

Evan Kelly Microbiology;
Brooke Wolff Biological Sciences;
Gabrielle Brautman Biological Sciences;
Olivia Phillips Biological Sciences

Mentors and/or Co-Authors :
Susan Carson Plant Biology
Devon Viscount Microbiology;
Eric Miller Microbiology;

Abstract Title : Survival and Mobility of an Intein within an Essential Protein of Mycobacteriophage Astraea

Abstract :
As students in the North Carolina State University “Phage Hunters” course, we isolated Astraea, a mycobacteriophage of the myoviridae morphotype. The Astraea genome was sequenced and classified in the C1 subcluster. We predicted two putative inteins near the 3’ end of the genome. An intein is a segment within a protein that is self-cleaved from the protein and the resulting polypeptides are rejoined. Both inteins were found to contain homing endonuclease genes (HEGs). A HEG is an enzyme capable of transferring genetic material from one phage genome to another; this can be potentially damaging as it disrupts gene function. One of the two inteins occurs within a gene predicted to encode terminase and is the focus of this work. Terminase is an essential protein responsible for packaging DNA into the capsid. The Astraea intein aligns with the mycobacteriophage Catera intein which has been shown biochemically to be a functional class three intein. We hypothesize that these inteins allow for the HEGs within them to be present without interfering with protein function, while the HEGs provide mobility of the intein between coinfecting bacteriophages. This arrangement demonstrates a complex level of coding capacity in a single region of the genome.