NUCLEOTIDE-SEQUENCE AND EXPRESSION ANALYSIS OF THE ACETOBACTER-XYLINUM PHOSPHOGLUCOMUTASE GENE

The Acetobacter xylinum gene (celB) encoding phosphoglucomutase (EC 5. 4.2.2) has previously been cloned by complementation of cellulose-nega tive mutants. In the present report the nucleotide sequence of a 2.0 k b DNA fragment containing celB is described. Expression analysis using the bacteriophage T7 RNA polymerase promoter phi 10 resulted in ident ification of a probable translational start codon of celB, and this co nclusion was confirmed by N-terminal amino acid sequencing of the reco mbinant protein. From the nucleotide sequence data it was deduced that celB encodes a protein with a calculated molecular mass of 59.6 kDa. A protein of similar size was visualized after in vitro transcription and translation, using the cloned 2.0 kb fragment as template. The res ults of an amino acid sequence comparison and a biochemical analysis i ndicated that the CelB protein is structurally and functionally relate d to the previously characterized human and rabbit phosphoglucomutases .