Linked Life Data

1722976

Source:http://linkedlifedata.com/resource/pubmed/id/1722976

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1992-2-27
pubmed:abstractText
We recently showed that RNase III can process a small stable RNA, precursor 10Sa RNA, that accumulates in an rne (RNase E) strain at non-permissive temperatures. Precursor 10Sa (p10Sa) RNA is processed to 10Sa RNA in two steps, the first step is catalyzed by RNase III in the presence of Mn2+ but not Mg2+. It was shown that RNase III cosediments with membrane preparation from wild type as well as RNase III overexpressing cells. However, the possibility of membrane preparation contamination with ribosomes could not be ruled out. Here we show that RNase III, E and P are not associated with ribosomes. E. coli cells were opened either by alumina grinding or by sonication and fractionated into cytosolic and pellet fractions. The characterization of membrane preparations was done by assaying NADH oxidase, a bona fide membrane enzyme. Ribosomes prepared by alumina grinding were found to be contaminated with small fragments of membrane which contained RNase III activity. RNase III and NADH oxidase activities were present in the ribosomal preparations which could be solubilized by reagents that dissolve the inner membrane. Isopycnic sucrose gradient centrifugation of the membrane and ribosomal preparations also confirmed that RNase III fractionated with the inner membrane. Similarly RNase P activity was found in the corresponding fractions when isopycnic centrifugation of membrane and ribosome preparations was carried out. RNase E activity was also found to be present mostly in the post-ribosomal supernatant. These findings show that RNase III, E and P are not ribosomal enzymes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0158-5231
pubmed:author
pubmed:issnType
Print
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
57-65
pubmed:dateRevised
2006-5-1
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
RNA processing enzymes RNase III, E and P in Escherichia coli are not ribosomal enzymes.
pubmed:affiliation
Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri 63110.
pubmed:publicationType
Journal Article