Disease relevance of all0265

• We conclude that in the natural habitat of Serratia marcescens where the supply of nutrients may become growth limiting the dimeric nuclease can fulfil its nutritive function more efficiently than a monomeric enzyme [1].
• In contrast to the monomeric Anabaena nuclease, the Serratia nuclease is a dimer of two identical subunits [1].
• Identification of a nuclease and host restriction-modification in the unicellular, aerobic nitrogen-fixing cyanobacterium Cyanothece sp [2].
• Genetic engineering of Escherichia coli to produce a 1:1 complex of the anabaena sp. PCC 7120 nuclease NucA and its inhibitor NuiA [3].

High impact information on all0265

• The artificial chromophoric substrate deoxythymidine 3',5'-bis-(p-nitrophenyl phosphate) is cleaved by NucA as well as by Serratia nuclease [4].
• Substitution of these residues by alanine leads to a large reduction in activity (<0.1 %), similarly as observed for Serratia nuclease demonstrating that both enzymes share a similar mechanism of catalysis with differences only in detail [4].
• The active site residue E163 seems to be the main target amino acid for inhibition of NucA by NuiA, but R93, R122 and R167 (corresponding to K55, R87, R131 in Serratia nuclease) are also involved in the NucA/NuiA interaction [4].
• The 410-kb alpha megaplasmid of the heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 was found to bear the nucA gene that encodes a sugar-nonspecific nuclease [5].
• The nuclease is easily released from intact cells by using water or buffer containing Triton X-100 [2].

References