TY - JOUR
T1 - A conserved nuclease domain in the archaeal Holliday junction resolving enzyme Hjc
AU - Kvaratskhelia, Mumuka
AU - Wardleworth, Benjamin N.
AU - Norman, David G.
AU - White, Malcolm F.
PY - 2000/8/18
Y1 - 2000/8/18
N2 - Holliday junction resolving enzymes are ubiquitous proteins that function in the pathway of homologous recombination, catalyzing the rearrangement and repair of DNA. They are metal ion-dependent endonucleases with strong structural specificity for branched DNA species. Whereas the eukaryotic nuclear enzyme remains unknown, an archaeal Holliday junction resolving enzyme, Hjc, has recently been identified. We demonstrate that Hjc manipulates the global structure of the Holliday junction into a 2-fold symmetric X shape, with local disruption of base pairing around the point of cleavage that occurs in a region of duplex DNA 3' to the point of strand exchange. Primary and secondary structural analysis reveals the presence of a conserved catalytic metal ion binding domain in Hjc that has been identified previously in several restriction enzymes. The roles of catalytic residues conserved within this domain have been confirmed by site-directed mutagenesis. This is the first example of this domain in an archaeal enzyme of known function as well as the first in a Holliday junction resolving enzyme.
AB - Holliday junction resolving enzymes are ubiquitous proteins that function in the pathway of homologous recombination, catalyzing the rearrangement and repair of DNA. They are metal ion-dependent endonucleases with strong structural specificity for branched DNA species. Whereas the eukaryotic nuclear enzyme remains unknown, an archaeal Holliday junction resolving enzyme, Hjc, has recently been identified. We demonstrate that Hjc manipulates the global structure of the Holliday junction into a 2-fold symmetric X shape, with local disruption of base pairing around the point of cleavage that occurs in a region of duplex DNA 3' to the point of strand exchange. Primary and secondary structural analysis reveals the presence of a conserved catalytic metal ion binding domain in Hjc that has been identified previously in several restriction enzymes. The roles of catalytic residues conserved within this domain have been confirmed by site-directed mutagenesis. This is the first example of this domain in an archaeal enzyme of known function as well as the first in a Holliday junction resolving enzyme.
UR - http://www.scopus.com/inward/record.url?scp=0034682793&partnerID=8YFLogxK
U2 - 10.1074/jbc.M003420200
DO - 10.1074/jbc.M003420200
M3 - Article
C2 - 10940317
AN - SCOPUS:0034682793
SN - 0021-9258
VL - 275
SP - 25540
EP - 25546
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 33
ER -