Sequence analysis of the glyW region in Escherichia coli

We have determined the DNA sequence of a 1-kilobase segment of the Escherichia coli chromosome. The segment contains glyW, a duplicate gene for tRNA3Gly, and its flanking regions. An insertion sequence, previously known to have occurred spontaneously within the sequenced fragment, was identified as IS1. Possible sites for initiation and termination of transcription were identified by comparing them with the sequences of model promoter regions and termination structures. The results suggest that the expression of glyW may depend upon the expression of the preceding gene, pgsA, by transcriptional or translational overlap, by cotranscription of these two genes, or both.