Linked Life Data

3017988

Source:http://linkedlifedata.com/resource/pubmed/id/3017988

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
27
pubmed:dateCreated
1986-10-23
pubmed:databankReference
pubmed:abstractText
The lc gene of the lambdoid bacteriophage PA-2 and the nmpC gene located on a defective lambdoid prophage in the 12-min region of the Escherichia coli K12 chromosome have been sequenced. The porin proteins encoded by these two genes were almost identical, with only 4 of the 365 residues of the precursor forms of the proteins being different. The Lc and NmpC proteins were strongly homologous to the OmpC, ompF, and PhoE proteins, with greater than 56% of the residues identical in each case. Sequencing of the region flanking the lc gene allowed precise positioning of this gene with respect to the rightward cos site of the phage and to sequences which are homologous between PA-2 and lambda. In wild-type strains of E. coli K12, the nmpC gene is not expressed and contains an IS5 insertion near the 3' end of the coding region. This insertion deletes 18 residues from the COOH terminus of NmpC protein and adds 8 residues from an open reading frame extending into IS5 sequence. Expression of this form of the gene in an expression vector plasmid demonstrated that this altered protein is still capable of being translocated to the outer membrane. Plasmid expression experiments using lc-nmpC hybrid genes show that it is the presence of the IS5 insertion which prevents expression of the porin in wild-type E. coli K12. In the nmpC mutant which expresses the protein, there has been a precise excision of the IS5 which regenerates a COOH terminus of NmpC protein which is identical to that of the Lc protein. Blot hybridization detected no mRNA transcripts from the wild-type nmpC gene, although transcripts were readily detected from the lc gene in PA-2 lysogens and from the nmpC mutant which has excised the IS5. This indicates that IS5 affects the production or stability of transcripts from the adjacent nmpC gene.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
261
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12723-32
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Structure of the lc and nmpC outer membrane porin protein genes of lambdoid bacteriophage.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.