Homologous genes for threonine tRNAs with the anticodon CGU have been identified in the region of the proBA operon of Escherichia coli and downstream from the fimbrial subunit gene of Pseudomonas aeruginosa. tRNAs with the anticodon CGU have not previously been identified from either of these bacterial species. Sequence analyses have shown that these genes are similar to other bacterial tRNA genes, and that the predicted structure conforms to the standard cloverleaf model, including retention of all invariant and semi-invariant bases. Analysis of upstream sequences suggests that these genes have associated promoters and are probably expressed in vivo.