Linked Life Data

9422763

Source:http://linkedlifedata.com/resource/pubmed/id/9422763

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-2-9
pubmed:abstractText
Drosophila RNase P and 3'-tRNase endonucleolytically process the 5' and 3' ends of tRNA precursors. We examined the processing kinetics of normal substrates and the inhibitory effect of the tRNA product on both processing reactions. The product is not a good RNase P inhibitor, with a KI approximately 7 times greater than the substrate KM of approximately 200 nM and is a better inhibitor of 3'-tRNase, with a KI approximately two times the KM of approximately 80 nM. We generated matrices of substitutions at positions G18/U55 and G19/C56 (two contiguous universally conserved D/T loop base pairs) in Drosophila tRNAHis precursors. More than half the variants display a significant reduction in their ability to be processed by RNase P and 3'-tRNase. Minimal substrates with deleted D and anticodon stems could be processed by RNase P and 3'-tRNase much like full-length substrates, indicating that D/T loop contacts and D arm/enzyme contacts are not required by either enzyme. Selected tRNAs that were poor substrates for one or both enzymes were further analyzed using Michaelis-Menten kinetics and by structure probing. Processing reductions arise principally due to an increase in KM with relatively little change in Vmax, consistent with the remote location of the sequence and structure changes from the processing site for both enzymes. Local changes in variant tRNA susceptibility to RNase T1 and RNase A did not coincide with processing disabilities.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
273
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1015-25
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Matrices of paired substitutions show the effects of tRNA D/T loop sequence on Drosophila RNase P and 3'-tRNase processing.
pubmed:affiliation
Natural Sciences/Biology, York College of the City University of New York, Jamaica, New York 11451, USA. louie@mbrs.york.cuny.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't