Structural investigations of the group II intron-encoded protein GsI-IIC

Abstract

Group II introns are a class of mobile ribozymes found in bacteria and eukaryotic organelles that self-splice from precursor RNAs. The resulting lariat intron RNA can then insert into new genomic DNA sites through a reverse splicing reaction. Collectively, this process of intron mobility is termed “retrohoming.” Mobile group II introns encode a reverse transcriptase (RT) that stabilizes the catalytically active form of the intron RNA for both the forward and reverse splicing reactions and also converts the integrated intron RNA into DNA. This work aims to elucidate the structure of bacterial group II intron-encoded RTs and ultimately determine how they function in intron mobility. Although efforts to crystallize group II introns RTs have been unsuccessful, small angle X-ray scattering studies in conjunction with homology modeling have provided new insights into the structure and function of these enzymes.