Genomic Heterogeneity in a Natural Archaeal Population Suggests a Model of tRNA Gene Disruption
(A) tRNAThr (GGU) gene locus with two introns (tRNAThr-II) found in the composite genome of C. subterraneum. (B) tRNAThr(GGU) gene locus with one intron (tRNAThr-I) found in clone JFF006_G04. (C) tRNAThr(GGU) fragment (tRNAThr-F) found in the composite genome. Positions in the tRNA are numbered as described previously . Nucleotides in the tRNA exon are shown in upper-case letters. Nucleotides conserved among A, B, and C, between A and B, and between B and C are shown as red, blue, and green, respectively. Black triangles indicate the locations of introns. The predicted anticodon is boxed. The 15-nt extensions at the 5′ and 3′ termini of the tRNA structures are defined randomly, and are not the actual leader or trailer sequences of potential pre-tRNAs.