Bannikova G E, Blagova E V, Varlamov V P, Morgunova E Iu, Dement'ev A A, Shliapnikov S V
Bioorg Khim. 1990 Dec;16(12):1678-82.
Two isoforms of an extracellular endonuclease, nuclease Sm1 and nuclease Sm2, 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 P2(1)2(1)2(1), a 69.0; b 106.7; c 74.8 A.
通过在亚氨基二乙酸 - 琼脂糖上以Cu2(+)形式进行配体交换色谱、磷酸纤维素色谱和DEAE - Toyopearl 650S色谱，从粘质沙雷氏菌菌株B10 M1的培养滤液中分离出一种细胞外核酸酶的两种同工型，即核酸酶Sm1和核酸酶Sm2。发现核酸酶Sm1和Sm2的pI分别为7.1和6.7。蛋白质的氨基酸分析和N端氨基酸测序表明这些酶之间具有显著的同源性。计算了核酸酶Sm2的二级结构。获得了空间群为P2(1)2(1)2(1)的核酸酶Sm2晶体，a为69.0；b为106.7；c为74.8埃。
