Chakraborty A K, Majumder H K
Molecular Parasitology Laboratory, Indian Institute of Chemical Biology, Calcutta.
Biochem Biophys Res Commun. 1991 Oct 15;180(1):279-85. doi: 10.1016/s0006-291x(05)81289-6.
An enzyme from Leishmania donovani that catenates monomeric pBR322 into huge catenanes has been isolated and characterized. The enzyme also decatenates kinetoplast DNA networks into covalently closed monomeric circles and relaxes supercoiled pBR322. The catenation, decatenation and relaxation reactions do not require ATP. The formation of topological isomers of unique linking numbers suggest that the enzyme is a type II DNA topoisomerase.
一种来自杜氏利什曼原虫的酶已被分离和鉴定，该酶可将单体pBR322连接成巨大的连环体。该酶还能将动质体DNA网络解开成共价封闭的单环，并使超螺旋pBR322松弛。连接、解链和松弛反应不需要ATP。独特连接数的拓扑异构体的形成表明该酶是一种II型DNA拓扑异构酶。
