Linked Life Data

15294156

Source:http://linkedlifedata.com/resource/pubmed/id/15294156

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2004-8-5
pubmed:databankReference
pubmed:abstractText
Bacterial transcription is regulated by the alarmone ppGpp, which binds near the catalytic site of RNA polymerase (RNAP) and modulates its activity. We show that the DksA protein is a crucial component of ppGpp-dependent regulation. The 2.0 A resolution structure of Escherichia coli DksA reveals a globular domain and a coiled coil with two highly conserved Asp residues at its tip that is reminiscent of the transcript cleavage factor GreA. This structural similarity suggests that DksA coiled coil protrudes into the RNAP secondary channel to coordinate a ppGpp bound Mg2+ ion with the Asp residues, thereby stabilizing the ppGpp-RNAP complex. Biochemical analysis demonstrates that DksA affects transcript elongation, albeit differently from GreA; augments ppGpp effects on initiation; and binds directly to RNAP, positioning the Asp residues near the active site. Substitution of these residues eliminates the synergy between DksA and ppGpp. Thus, the secondary channel emerges as a common regulatory entrance for transcription factors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0092-8674
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
118
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
297-309
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Regulation through the secondary channel--structural framework for ppGpp-DksA synergism during transcription.
pubmed:affiliation
Cellular Signaling Laboratory, Mikazuki-cho, Sayo, Hyogo 679-5148, Japan.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't