Processing of Peptides and Proteins

Abstract

The invention provides novel methionine aminopeptidase enzymes and their use.

1 . An  E. coli  aminopeptidease variant wherein residues Y168, M206, and/or Q233 are modified such that the variant exhibits extended substrate specificity in P1′ position for Asn, Leu, Ile, Phe, His, Gln, or Trp in addition to wild type substrate amino acids. 
     
     
         2 . The variant of  claim 1 , wherein the variant includes a modification in position 168. 
     
     
         3 . The variant of  claim 1 , wherein the variant includes a modification in position 206. 
     
     
         4 . The variant of  claim 1 , wherein the variant includes a modification in position 233. 
     
     
         5 . The variant of  claim 1 , wherein the variant includes a modification in positions 206 and 233. 
     
     
         6 . The variant of  claim 1 , wherein the variant includes a modification in positions 168 and 206. 
     
     
         7 . The variant of  claim 1 , wherein the variant includes a modification in positions 168 and 233. 
     
     
         8 . The variant of  claim 1 , wherein the variant includes a modification in positions 168, 206, and 233. 
     
     
         9 . The variant of  claim 1 , wherein position 168 is an Ala. 
     
     
         10 . The variant of  claim 1 , wherein position 206 is an Ala. 
     
     
         11 . The variant of  claim 1 , wherein position 233 is an Ala. 
     
     
         12 . The variant of  claim 2 , wherein position 168 is an Ala. 
     
     
         13 . The variant of  claim 3 , wherein position 168 is an Ala. 
     
     
         14 . The variant of  claim 4 , wherein position 168 is an Ala. 
     
     
         15 . An  E.coli  methionine aminopeptidase having an amino acid sequence selected from Seq. id. No. 3, Seq. id. No. 5, Seq. id. No. 7, and Seq. id. No. 9.