We have constructed a three-dimensional model of the Ll.LtrB intron of Lactococcus lactis, based on cross-linking data and other structural constraints:
Dai et al. 2008. A three-dimensional model of a group II intron RNA and its interaction with the intron-encoded reverse transcriptase. Molecular Cell 30: 472-485.Click images for larger view.
A.
B. C.
Legend
Three-dimensional model of Ll.LtrB-ΔORF lariat RNA and ligated exons.
A. Views of the exon-binding face and opposite face, with cylinders representing helices and black tubes depicting the phosphate backbone of ligated exons. Domains are colored as in Panel B. Single-strands are shown in gray.
B. Color coding of RNA domains. A secondary structure of the Ll.LtrB intron RNA is shown, with boxed nucleotides indicating single-strands for which specific conformations were predicted based on crystal structures of tetraloop-receptor interactions.
C. Schematic showing the arrangement of domains in the ribozyme model.