PURIFICATION AND PROPERTIES OF HUMAN DNA HELICASE-VI

被引：19

作者：

TUTEJA, N ^{[1
]}

OCHEM, A ^{[1
]}

TANEJA, P ^{[1
]}

TUTEJA, R ^{[1
]}

SKOPAC, D ^{[1
]}

FALASCHI, A ^{[1
]}

机构：

[1] INT CTR GENET ENGN & BIOTECHNOL,I-34012 TRIESTE,ITALY

来源：

NUCLEIC ACIDS RESEARCH | 1995年 / 23卷 / 13期

关键词：

D O I：

10.1093/nar/23.13.2457

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

A novel ATP-dependent DNA unwinding enzyme, called human DNA helicase VI (HDH VI), was purified to apparent homogeneity from HeLa cells and characterized, From 327 g of cultured cells, 0.44 mg of pure enzyme was recovered, free of DNA polymerase, ligase, topoisomerase, nicking and nuclease activities, The enzyme behaves as a monomer having an M(r) of 128 kDa, whether determined with SDS-PAGE, or in native conditions, Photoaffinity labelling with [alpha-P-32]ATP labelled the 128 kDa protein, Only ATP or dATP hydrolysis supports the unwinding activity for which a divalent cation (Mg2+ > Mn2+) is required, HDH VI unwinds exclusively DNA duplexes with an annealed portion <32 bp and prefers a replication fork-like structure of the substrate, It cannot unwind blunt-end duplexes and is inactive also on DNA-RNA or RNA-RNA hybrids. HDH VI unwinds DNA unidirectionally by moving in the 3' to 5' direction along the bound strand.

引用

页码：2457 / 2463

页数：7

共 32 条

[1]

CSORDASTOTH E, 1993, NUCLEIC ACIDS RES, V21, P3257

[2] PROTEINS CONTROLLING THE HELICAL STRUCTURE OF DNA [J].