Recombinant DNA, transformed host microorganism and method for producing a polypeptide having mutarotase activity

A recombinant DNA molecule coding for a polypeptide having the biological activity of mutarotase and capable of being expressed in a host microorganism when combined with a vector, comprising, in a 5' to 3' direction:

• a promoter sequence, operably linked to
• a Shine-Dalgarno sequence derived from the beginning of a tetracycline-repressor gene, operably linked to
• a first ATG starting codon, fused in frame with
• a recombinant structural gene coding for mutarotase derived from the genome of a mutarotase-producing microorganism of the genus Acinetobacter,
• wherein
• the genomic sequence of the Acinetobacter mutarotase gene from which the recombinant structural gene is derived comprises
• a second ATG starting codon,
• a leader sequence and
• a coding sequence, and the recombinant structural gene comprises a modified genomic Acinetobacter mutarotase sequence wherein
• the leader sequence has been removed, and the coding sequence directly fused in frame 3' to the second ATG starting codon has been modified to the nucleotide sequence
• X TTG AAT GTA AAA CCA,
• wherein X is TCT AGA or CGA ACG;
• wherein
• the Shine-Dalgarno sequence and the promoter sequence are derived from the host microorganism in which the mutarotase is capable of being expressed.