Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
41
pubmed:dateCreated
1995-12-4
pubmed:abstractText
RecBCD enzyme is a multifunctional nuclease that is essential for the major pathway of homologous genetic recombination in Escherichia coli. It has a potent helicase activity that uses ATP hydrolysis to unwind very long stretches of DNA. The functional form of RecBCD enzyme has been unclear, since M(r) of 250,000-655,000 have been previously reported. We have isolated two oligomeric forms of the enzyme, one (monomeric) containing a single copy of the RecB, RecC, and RecD polypeptides, and the other (dimeric) containing two copies of each polypeptide. We show here that the monomeric form of the enzyme (M(r) approximately 330,000) can form a stable initiation complex on the end of ds DNA. Depending on the nature of the ds end, KD estimates ranged from approximately 0.1 nM to approximately 0.7 nM in the presence of Mg2+ ions, which enhanced but was not required for binding. We further showed that the complex of monomeric RecBCD enzyme and a ds DNA end was competent to unwind DNA. A general model for the action of helicases has been proposed that uses repeated conformational changes between two states of a complex between DNA and a dimeric form of the enzyme. Our results make such a model unlikely for RecBCD enzyme.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
24451-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:7592660-Base Sequence, pubmed-meshheading:7592660-Centrifugation, Density Gradient, pubmed-meshheading:7592660-DNA, pubmed-meshheading:7592660-DNA Helicases, pubmed-meshheading:7592660-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:7592660-Escherichia coli, pubmed-meshheading:7592660-Escherichia coli Proteins, pubmed-meshheading:7592660-Exodeoxyribonuclease V, pubmed-meshheading:7592660-Exodeoxyribonucleases, pubmed-meshheading:7592660-Kinetics, pubmed-meshheading:7592660-Macromolecular Substances, pubmed-meshheading:7592660-Molecular Sequence Data, pubmed-meshheading:7592660-Molecular Weight, pubmed-meshheading:7592660-Oligodeoxyribonucleotides, pubmed-meshheading:7592660-Protein Binding, pubmed-meshheading:7592660-Recombinant Proteins, pubmed-meshheading:7592660-Substrate Specificity
pubmed:year
1995
pubmed:articleTitle
Monomeric RecBCD enzyme binds and unwinds DNA.
pubmed:affiliation
Fred Hutchinson Cancer Research Center, Seattle, Washington 98104, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.