Highly productive alpha-amylases

Abstract

The invention relates to mutant α-amylases that may be produced at high yield from recombinant microorganisms.

1 . A mutant α-amylase which is derived from an α-amylase having an amino acid sequence represented by SEQ ID No. 2 or showing at least 60% homology thereto by substitution or deletion of at least one amino acid residue corresponding to any one of Pro 18 , Gln 86 , Glu 130 , Asn 154 , Arg 171 , Ala 186 , Glu 212 , Val 222 , Tyr 243 , Pro 260 , Lys 269 , Glu 276 , Asn 277 , Arg 310 , Glu 360 , Gln 391 , Trp 439 , Lys 444 , Asn 471  and Gly 476  of the amino acid sequence.  
     
     
         2 . (canceled)  
     
     
         3 . A mutant α-amylase according to  claim 1 , wherein the substitution or deletion of at least one amino acid residue is substitution of the amino acid residue corresponding to Pro 18  with Ser or Thr, the amino acid residue corresponding to Gln 86  with Glu, the amino acid residue corresponding to Glu 130  with Val or Gln, the amino acid residue corresponding to Asn 154  with Asp, the amino acid residue corresponding to Arg 171  with Cys or Gln, the amino acid residue corresponding to Ala 186  with Val or Asn, the amino acid residue corresponding to Glu 212  with Asp, the amino acid residue corresponding to Val 222  with Glu, the amino acid residue corresponding to Tyr 243  with Cys or Ser, the amino acid residue corresponding to Pro 260  with Glu, the amino acid residue corresponding to Lys 269  with Gln, the amino acid residue corresponding to Glu 276  with His, the amino acid residue corresponding to Asn 277  with Ser or Phe, the amino acid residue corresponding to Arg 310  with Ala, the amino acid residue corresponding to Glu 360  with Gln, the amino acid residue corresponding to Gln 391  with Glu, the amino acid residue corresponding to Trp 439  with Arg, the amino acid residue corresponding to Lys 444  with Arg, the amino acid residue corresponding to Asn 471  with Asp or Glu, or the amino acid residue corresponding to Gly 476  with Asp.  
     
     
         4 . (canceled)  
     
     
         5 . A gene encoding a mutant α-amylase as claimed in  claim 1 , or a vector containing said gene.  
     
     
         6 . A cell transformed by a vector as claimed in  claim 5 .  
     
     
         7 . A method for producing a mutant α-amylase, which comprises cultivating a transformant cell as claimed in  claim 6 .  
     
     
         8 . A detergent composition comprising a mutant α-amylase as claimed in  claim 1.