Linked Life Data

9153418

Source:http://linkedlifedata.com/resource/pubmed/id/9153418

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
1997-6-9
pubmed:abstractText
The terminase enzyme from bacteriophage lambda is responsible for excision of a single genome from a concatameric DNA precursor and its insertion into an empty viral procapsid. The enzyme possesses a site-specific endonuclease activity which is responsible for excision of the viral genome and the formation of the 12 base-pair single-stranded "sticky" ends of mature lambda DNA. We have previously reported a kinetic analysis of the endonuclease activity of lambda terminase which showed an enzyme concentration-dependent change in the kinetic time course of the reaction [Tomka, M. A., & Catalano, C. E. (1993b) J. Biol. Chem. 268, 3056-3065]. We presented a model which suggested that the rate-limiting step in the nuclease reaction was the assembly of a catalytically competent prenicking complex. Here, we provide additional evidence for a slow assembly step in the nuclease reaction and demonstrate that the observed rate is affected by protein concentration, but not by the length of the DNA substrate. Consistent with our model, preincubation of terminase with DNA also yields an observable fast phase of the reaction, but only when large (> or = 3 kb) DNA substrates are used. Finally, we present data which demonstrate that phage lambda terminase can efficiently utilize DNA from the closely related phage phi21 as an endonuclease substrate and that the enzyme binds efficiently to the cosB region of both phage genomes. The implications of these results with respect to the assembly of a catalytically competent nucleoprotein complex required to initiate genome packaging are discussed.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5777-85
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Kinetic analysis of the endonuclease activity of phage lambda terminase: assembly of a catalytically competent nicking complex is rate-limiting.
pubmed:affiliation
Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Health Sciences Center, Denver 80262, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.