Rigden Daniel J, Setlow Peter, Setlow Barbara, Bagyan Irina, Stein Richard A, Jedrzejas Mark J
National Centre of Genetic Resources and Biotechnology, Cenargen/Embrapa, Brasília, Brazil, D.F. 70770-900.
Protein Sci. 2002 Oct;11(10):2370-81. doi: 10.1110/ps.0216802.
The prfA gene product of Gram-positive bacteria is unusual in being implicated in several cellular processes; cell wall synthesis, chromosome segregation, and DNA recombination and repair. However, no homology of PrfA with other proteins has been evident. Here we report a structural relationship between PrfA and the restriction enzyme PvuII, and thereby produce models that predict that PrfA binds DNA. Indeed, wild-type Bacillus stearothermophilus PrfA, but not a catalytic site mutant, nicked one strand of supercoiled plasmid templates leaving 5'-phosphate and 3'-hydroxyl termini. This activity, much lower on linear or relaxed circular double-stranded DNA or on single-stranded DNA, is consistent with a role for this protein in chromosome segregation, DNA recombination, or DNA repair.
革兰氏阳性菌的prfA基因产物不同寻常，它涉及多种细胞过程，如细胞壁合成、染色体分离以及DNA重组与修复。然而，PrfA与其他蛋白质之间并未发现明显的同源性。在此，我们报告了PrfA与限制性内切酶PvuII之间的结构关系，进而构建了预测PrfA可结合DNA的模型。实际上，野生型嗜热脂肪芽孢杆菌的PrfA（而非催化位点突变体）切开了超螺旋质粒模板的一条链，留下了5'-磷酸和3'-羟基末端。这种活性在线性或松弛的环状双链DNA或单链DNA上要低得多，这与该蛋白在染色体分离、DNA重组或DNA修复中的作用相符。
