Molecular Charcterization of tatD DNAse Gene from Ralstonia paucula RA4T Soil Bacterium

Ralstonia paucula strain RA4T, a gram negative, nonspore forming, motile bacterium having pos itive catalase and oxidase test, was isolated from surface soil. Twin arginine translocation protein type D (TatD) is shown to be located in cytoplasm and exhibits magnesiumdependent DNase. A tatD DNase gene was isolated and cloned from Ralstonia paucula RA4T genome. Nucleotide sequence analysis of the gene revealed 813 nucleotides encoding a protein of 270 amino acid residues. The tatD gene showed a high simi larity to homolog gene from Ralstonia pickettii strain 12D. The deduced polypeptide sequence of TatD DNase from R. paucula RA4T had a typical catalytic site, HHPLDEHRHDP, and its calculated molecular mass and predicted isoelectric point were 29616 Da and 5.33, respectively. The deduced amino acid sequence showed a high degree of similarity to TatD DNase isoforms from Ralstonia genus and other sources. Predicted three dimensional structure of TatD confirmed the presence of active site and theoretical function as DNase.

Ralstonia paucula، ِDNase, TatD, Soil bactria