Streptomyces aureofaciens B96 produces several intra- and extracellular enzymes with deoxyribonuclease activity. According to the sequence of the previously published gene exoSc from S. coelicolor A3(2), the DNA sequence from S. aureofaciens B96 was amplified, cloned and expressed in E. coli. The protein product of exoSa gene, recExoSa, was also an exonuclease with DNAase and 5'-phosphomonoesterase activities at optimum temperature 37 degrees C and pH 8.0. It degraded only linear DNA (chromosomal, double-stranded and single-stranded) and linear plasmid DNA from both ends, with a preference to blunt ends in comparison with overhang ends. The purified enzyme exhibited no RNAase activity. Both exoSc and exoSa genes were interrupted by the apramycin resistance gene; constructed fragments were transformed into particular streptomyces protoplasts. Mutation caused by exoSa disruption in S. aureofaciens chromosome and mutation by interrupted exoSc in S. coelicolor were lethal.

• MeSH
• Bacterial Proteins chemistry   genetics   isolation & purification   metabolism   MeSH
• Deoxyribonucleases chemistry   genetics   isolation & purification   metabolism   MeSH
• Exonucleases chemistry   genetics   isolation & purification   metabolism   MeSH
• Phosphoric Monoester Hydrolases chemistry   genetics   isolation & purification   metabolism   MeSH
• Cloning, Molecular MeSH
• Molecular Sequence Data MeSH
• Amino Acid Sequence MeSH
• Sequence Alignment MeSH
• Enzyme Stability MeSH
• Streptomyces aureofaciens chemistry   enzymology   genetics   MeSH
• Streptomyces coelicolor chemistry   enzymology   genetics   MeSH
• Substrate Specificity MeSH
• Gene Silencing * MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Bacterial Proteins MeSH
• Deoxyribonucleases MeSH
• Exonucleases MeSH
• Phosphoric Monoester Hydrolases MeSH