DNA TOPOISOMERASE AND RECOMBINASE ACTIVITIES IN NAE-I RESTRICTION-ENDONUCLEASE

被引：55

作者：

JO, K

TOPAL, MD

机构：

[1] UNIV N CAROLINA, SCH MED, DEPT BIOCHEM & BIOPHYS, LINEBERGER COMPREHENS CANC CTR, CHAPEL HILL, NC 27599 USA

[2] UNIV N CAROLINA, SCH MED, DEPT PATHOL, CHAPEL HILL, NC 27599 USA

来源：

SCIENCE | 1995年 / 267卷 / 5205期

关键词：

D O I：

10.1126/science.7892605

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Nae I endonuclease must bind to two DNA sequences for cleavage. Examination of the amino acid sequence of Nae I uncovered similarity to the active site of human DNA ligase I, except for leucine 43 in Nae I instead of the lysine essential for ligase activity. Changing leucine 43 to lysine 43 (L43K) changed Nae I activity: Nae I-L43K relaxed supercoiled DNA to yield DNA topoisomers and recombined DNA to give dimeric molecules. Interruption of the reactions of Nae I and Nae I-L43K with DNA demonstrated transient protein-DNA covalent complexes. These findings imply coupled endonuclease and ligase domains and link Nae I endonuclease to the topoisomerase and recombinase protein families.

引用

页码：1817 / 1820

页数：4

共 27 条

[21]

THRESHER R, 1992, METHOD ENZYMOL, V211, P481

[22] CHANGING ENDONUCLEASE ECORII TYR308 TO PHE ABOLISHES CLEAVAGE BUT NOT RECOGNITION - POSSIBLE HOMOLOGY WITH THE INT-FAMILY OF RECOMBINASES [J].