Linked Life Data

11254381

Source:http://linkedlifedata.com/resource/pubmed/id/11254381

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2001-3-20
pubmed:databankReference
pubmed:abstractText
DNA replication and cellular survival requires efficient removal of RNA primers during lagging strand DNA synthesis. In eukaryotes, RNA primer removal is initiated by type 2 RNase H, which specifically cleaves the RNA portion of an RNA-DNA/DNA hybrid duplex. This conserved type 2 RNase H family of replicative enzymes shares little sequence similarity with the well-characterized prokaryotic type 1 RNase H enzymes, yet both possess similar enzymatic properties. Crystal structures and structure-based mutational analysis of RNase HII from Archaeoglobus fulgidus, both with and without a bound metal ion, identify the active site for type 2 RNase H enzymes that provides the general nuclease activity necessary for catalysis. The two-domain architecture of type 2 RNase H creates a positively charged binding groove and links the unique C-terminal helix-loop-helix cap domain to the active site catalytic domain. This architectural arrangement apparently couples directional A-form duplex binding, by a hydrogen-bonding Arg-Lys phosphate ruler motif, to substrate-discrimination, by a tyrosine finger motif, thereby providing substrate-specific catalytic activity. Combined kinetic and mutational analyses of structurally implicated substrate binding residues validate this binding mode. These structural and mutational results together suggest a molecular mechanism for type 2 RNase H enzymes for the specific recognition and cleavage of RNA in the RNA-DNA junction within hybrid duplexes, which reconciles the broad substrate binding affinity with the catalytic specificity observed in biochemical assays. In combination with a recent independent structural analysis, these results furthermore identify testable molecular hypotheses for the activity and function of the type 2 RNase H family of enzymes, including structural complementarity, substrate-mediated conformational changes and coordination with subsequent FEN-1 activity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-2836
pubmed:author
pubmed:copyrightInfo
Copyright 2001 Academic Press.
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
307
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
541-56
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:11254381-Amino Acid Sequence, pubmed-meshheading:11254381-Archaeal Proteins, pubmed-meshheading:11254381-Archaeoglobus fulgidus, pubmed-meshheading:11254381-Catalysis, pubmed-meshheading:11254381-Catalytic Domain, pubmed-meshheading:11254381-Cloning, Molecular, pubmed-meshheading:11254381-Cobalt, pubmed-meshheading:11254381-Crystallography, X-Ray, pubmed-meshheading:11254381-DNA Mutational Analysis, pubmed-meshheading:11254381-DNA Replication, pubmed-meshheading:11254381-Kinetics, pubmed-meshheading:11254381-Metalloproteins, pubmed-meshheading:11254381-Models, Molecular, pubmed-meshheading:11254381-Molecular Sequence Data, pubmed-meshheading:11254381-Protein Structure, Secondary, pubmed-meshheading:11254381-RNA, pubmed-meshheading:11254381-Recombinant Proteins, pubmed-meshheading:11254381-Ribonuclease H, pubmed-meshheading:11254381-Sequence Homology, Amino Acid
pubmed:year
2001
pubmed:articleTitle
Structural biochemistry of a type 2 RNase H: RNA primer recognition and removal during DNA replication.
pubmed:affiliation
Department of Molecular Biology, Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA 92037, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't