Separation of isoforms of a Serratia marcescens endonuclease and cristallization of the enzyme

G. E. Bannikova, E. V. Blagova, V. P. Varlamov, E. Yu. Morgunova, A. A. Dementiev, S. V. Shlyapnikov

V. A. Engelhardt Institute of Molecular Biology Bioengineriya Centre, Moscow; Institute of Crystallography, Academy of Sciences of the USSR, Moscow; V. A. Engelhardt Institute of Molecular Biology, Academy of Sciences of the USSR, Moscow

Abstract: Two isoforms of an extracellular endonuclease, nuclease Smr and nuclease Sm2r were isolated from the culture filtrate of Serratia marcescens strain B10 M1 by the ligand-exchange chromatography on iminodiacetate-agarose in Cu2+-form, and chromatography on phosphocellulose and DEAE-Toyopearl 650S. The pI for nucleases Sm1 and Sm2 were found to be 7,1 and 6,7, respectively. The amino acid analysis and N-terminal amino acid sequencing of the proteins showed a significant degree of homology between the enzymes. The secondary structure of nuclease Sm2 was calculated. Crystals of nuclease Sm2 were-obtained with the space group P212121, a 69,0; b 106,7; c 74,8 A.

Russian Journal of Bioorganic Chemistry 1990, 16 (12):1678-1682

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