ALPHA-1, 4-GALACTOSYLTRANSFERASE (CgtD) FROM CAMPYLOBACTER JEJUNI

Abstract

α-1,4-galactosyltransferase (CgtD) polypeptides, nucleic acids that encode the polypeptides, including a polypeptide from Campylobacter jejuni strain LIO87 have been isolated and characterized A method of producing a galactosylated saccharide comprising contacting an acceptor saccharide containing a terminal galactose, a donor substrate comprising a galactose moiety and one of the CgtD polypeptides is described.

1 . A method of producing a galactosylated product saccharide, the method comprising the step of:
 a) contacting an acceptor substrate with a donor substrate comprising a galactose moiety and an isolated or recombinant α-1,4-galactosyltransferase polypeptide with at least 80% identity to SEQ ID NO:2; and   b) allowing transfer of a galactose moiety to the acceptor saccharide to occur, thereby producing the galactosylated product saccharide.   
     
     
         2 . The method of  claim 1 , wherein the α-1,4-galactosyltransferase polypeptide comprises an amino acid sequence with at least 90% identity to SEQ ID NO:2. 
     
     
         3 . The method of  claim 1 , wherein the α-1,4-galactosyltransferase polypeptide comprises an amino acid sequence with at least 95% identity to SEQ ID NO:2. 
     
     
         4 . The method of  claim 1 , wherein the α-1,4-galactosyltransferase polypeptide comprises an amino acid sequence of SEQ ID NO:2. 
     
     
         5 . The method of  claim 1 , wherein the method is performed at a commercial scale of production. 
     
     
         6 . A reaction mixture comprising an isolated or recombinant α-1,4-galactosyltransferase polypeptide, wherein the α-1,4-galactosyltransferase polypeptide comprises an amino acid sequence with at least 80% identity to SEQ ID NO:2, and wherein the α-1,4-galactosyltransferase polypeptide transfers a galactose moiety from a donor substrate to an acceptor substrate. 
     
     
         7 . The reaction mixture of  claim 6 , wherein the α-1,4-galactosyltransferase polypeptide comprises an amino acid sequence with at least 90% identity to SEQ ID NO:2. 
     
     
         8 . The reaction mixture of  claim 6 , wherein the α-1,4-galactosyltransferase polypeptide comprises an amino acid sequence with at least 95% identity to SEQ ID NO:2. 
     
     
         9 . The reaction mixture of  claim 6 , wherein the α-1,4-galactosyltransferase polypeptide comprises an amino acid sequence of SEQ ID NO:2. 
     
     
         10 . An isolated nucleic acid the encodes an α-1,4-galactosyltransferase polypeptide of  claim 6 , wherein the isolated nucleic acid comprises a nucleic acid sequence with at least 80% identity to SEQ ID NO: 1. 
     
     
         11 . The isolated nucleic acid of  claim 10 , wherein the isolated nucleic acid comprises a nucleic acid sequence with at least 90% identity to SEQ ID NO: 1. 
     
     
         12 . The isolated nucleic acid of  claim 10 , wherein the isolated nucleic acid comprises a nucleic acid sequence with at least 95% identity to SEQ ID NO: 1. 
     
     
         13 . The isolated nucleic acid of  claim 10 , wherein the isolated nucleic acid comprises a nucleic acid sequence of SEQ ID NO: 1. 
     
     
         14 . An expression vector comprising a nucleic acid sequence of  claim 10 . 
     
     
         15 . A host cell comprising the expression vector of  claim 14 .