ANALYSIS OF THE ESCHERICHIA-COLI GENOME .6. DNA-SEQUENCE OF THE REGION FROM 92.8 THROUGH 100 MINUTES

The 338.5 kb of the Escherichia coli genome described here together wi th previously described segments bring the total of contiguous finishe d sequence of this genome to >1 Mb. Of 319 open reading frames (ORFs) found in this 338.5 kb segment, 147 (46%) are potential new genes. The positions of several genes which had been previously located here by mapping or partial sequencing have been confirmed. Several ORFs have f unctions suggested by similarities to other characterised genes but ca nnot be assigned with certainty. Fifteen of the ORFs of unknown functi on had been previously sequenced. Eight transfer RNAs are encoded in t he region and there are two grey holes in which no features were found . The attachment site for phage P4 and three insertion sequences were located. The region was also analysed for chi sites, bend sites, REP e lements and other repeats. A computer search identified potential prom oters and tentative transcription units were assigned. The occurrence of the rare tetramer CTAG was analysed in 1.6 Mb of contiguous E. coli sequence. Hypotheses addressing the rarity and distribution of CTAG a re discussed.