2-Deoxy-Scyllo-Inosose Synthase

Abstract

An object of the present invention is to provide a DOI synthase having properties such as stability to heat and pH, which are superior to those of conventional enzymes, and a method for producing DOI using the above-mentioned enzyme. The present invention provides a 2-deoxy-scyllo-inosose synthase having the properties described in the following (1), (2), (4), (6) and (7), and also having the properties described in the following (3) and/or (5): (1) action: the enzyme has a function to convert glucose-6-phosphate to 2-deoxy-scyllo-inosose; (2) optimum pH range: pH 7.0 to 7.7; (3) stable pH range: pH 6.0 to 8.0; (4) optimum temperature range: 55° C. to 70° C.; (5) stable temperature range: 20° C. to 46° C.; (6) coenzyme used: NAD + ; and (7) molecular weight: 39,000 to 42,000.

1 - 15 . (canceled) 
     
     
         16 . A method of producing 2-deoxy-scyllo-inosose from glucose-6-phosphate, wherein a microorganism capable of expressing 2-deoxy-scyllo-inosose synthase is cultured in a medium containing a cobalt ion at a concentration of 0.1 to 50 mg/L in cobalt chloride hexahydrate equivalent. 
     
     
         17 . The method according to  claim 16 , wherein a raw material that contains polysaccharide comprising glucose as a constituent, or glucose, is used. 
     
     
         18 . The method according to  claim 16 , wherein the 2-deoxy-scyllo-inosose. synthase is a 2-deoxy-scyllo-inosose synthase having the properties described in the following (1), (2), (4), (6) and (7), and also having the properties described in the following (3) and/or (5):
 (1) action: the enzyme has a function to convert glucose-6-phosphate to 2-deoxy-scyllo-inosose;   (2) optimum pH range: pH 7.0 to 7.7;   (3) stable pH range: pH 6.0 to 8.0;   (4) optimum temperature range: 55° C. to 70° C.;   (5) stable temperature range: 20° C. to 50° C.;   (6) coenzyme used: NAD+; and   (7) molecular weight: 39,000 to 42,000.   
     
     
         19 . The method according to  claim 18 , wherein the 2-deoxy-scyllo-inosose synthase has the property described in the following (8):
 (8) specific activity: 1.0 j·lmol/min/mg or greater (reaction temperature: 65° C.).   
     
     
         20 . The method according to  claim 18 , wherein the 2-deoxy-scyllo-inosose synthase has the property described in the following (9):
 (9) cofactor: activity being improved by addition of Co2+ ion.   
     
     
         21 . The method according to  claim 18 , wherein the stable temperature range is 20° C. to 50° C. 
     
     
         22 . The method according to  claim 18 , wherein the 2-deoxy-scyllo-inosose synthase has any one of the following amino acid sequences:
 (a) the amino acid sequence shown in any one of SEQ ID NOS: 2, 4, 6, 8, 10 and 12;   (b) an amino acid sequence having sequence identity of 80% or more with the amino acid sequence shown in any one of SEQ ID NOS: 2, 4, 6, 8, 10 and 12, and having high temperature stability and/or wide range pH stability; and   (c) an amino acid sequence comprising a deletion, addition and/or substitution of one or multiple amino acids with respect to the amino acid sequence shown in any one of SEQ ID NOS: 2, 4, 6, 8, 10 and 12, and having high temperature stability and/or wide range pH stability.