ISSN 1002-1027  CN 11-2952/G2

Acta scientiarum naturalium Universitatis Pekinensis

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Characterization of a Gentisate 1,2-dioxygenase from Ralstonia solanacearum GMI1000

LIU Dongqi1ZHU Shunni,NI Jinren   

  1. Department ofEnvironmental Engineering, Peking University, Beijing,100871;1Corresponding Author, E-mail: liudongqi@iee.pku.edu.cn?
  • Received:2007-01-09 Online:2007-11-20 Published:2007-11-20

Abstract: The gene encoding gentisate 1,2-dioxygenase from a soil-borne Gram-negative bacterium, Ralstonia solanacearum GMI1000, was cloned and overexpressed in E. coli. The resulting product incorporated a (His) 6 tag was purified to homogeneity from the harvested cell extracts by affinity chromatography. SDS-PAGE showed that the polypeptide exhibited an approximate molecular mass of 38 kDa. The optimal temperature and pH for gentisate cleavage catalyzed by the enzyme were 30 ℃ and 7.5, respectively. The Km of the enzyme was determined to be 56 μmol/L. The pI was 4.6-4.8. The active site of the gentisate 1,2-dioxygenase with gentisate was also modeled.