Group II introns are novel genetic elements with two remarkable properties. They are catalytic RNAs (ribozymes) that can self-splice in the absence of protein. They are also retroelements that encode a reverse transcriptase and spread selfishly to new sites in genomes. In addition to these properties, group II introns are of great evolutionary interest because they are considered to be the ancestors of spliceosomal introns, which are the major introns in humans.
In studying group II introns, we make much use of the public sequence databases, in order to gain information about the overall distribution of introns, the variations in their structures, and inferred mobility properties. This information provides a foundation for evaluating the diversity of the introns and for choosing introns to characterize experimentally. For example, one identified subclass (bacterial class C, or IIC) was observed in genome sequences to be always located after transcriptional terminators, which implies a mobility behavior of inserting at the end of transcription units. This property was investigated and confirmed, for the B.h.I1 intron of Bacillus halodurans, and represents a new strategy for a selfish DNA to avoid inserting into coding sequences and damaging its host (Robart et al., 2006). Our experimental work continues to focus on the IIC introns, an understudied subclass of group II introns. Research interests include:
1) Characterization of the self-splicing properties of the B.h.I1 intron;
2) Investigation of mobility properties of B.h.I1, both in vitro and in vivo;
3) Exploration of the structural diversity of the intron RNAs;
4) Evolutionary analyses of group II introns to help infer their history.