Sequence analysis of D-xylose isomerase gene from Escherichia coli

Gene coding for E. coli D-xylose isomerase was cloned into the plasmid pWR13 from the plasmid pXO100 containing D-xylose operon. Several subclones harboring DNA fragments of different size obtained by step- by-step shortening with Bal31 nuclease were directly sequenced. The complete nucleotide sequence of the 1.6kb DNA fragment carrying D-xylose isomerase gene was determined. The structural gene of 1320 nucleotides codes for a protein of 440 amino acids. The additional 209 nucleotides at 5' end and 82 nucleotides at 3' end include Shine-Dalgarno ribosome-binding site and the transcriptional termination codon, respectively.