Linked Life Data

15557327

Source:http://linkedlifedata.com/resource/pubmed/id/15557327

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2005-2-7
pubmed:abstractText
In Escherichia coli, the Tat system promotes the membrane translocation of a subset of exported proteins across the cytoplasmic membrane. Four genes (tatA, tatB, tatC, and tatE) have been identified that encode the components of the E. coli Tat translocation apparatus. Whereas TatA and TatE can functionally substitute for each other, the TatB and the TatC proteins have been shown to perform distinct functions. In contrast to Tat systems of the ABC(E) type found in E. coli and many other bacteria, some microorganisms possess a TatAC-type translocase that consists of TatA and TatC only, suggesting that, in these systems, TatB is not required or that one of the remaining components (TatA or TatC) additionally takes over the TatB function. We have addressed the molecular basis for the difference in subunit composition between TatABC(E) and TatAC-type systems by using a genetic approach. A plasmid-encoded E. coli minimal Tat translocase consisting solely of TatA and TatC was shown to mediate a low level translocation of a sensitive Tat-dependent reporter protein. Suppressor mutations in the minimal Tat translocase were isolated that compensate for the absence of TatB and that showed substantial increases in translocation activities. All of the mutations mapped to the extreme amino-terminal domain of TatA. No mutations affecting TatC were identified. These results suggest that in TatAC-type systems, the TatA protein represents a bifunctional component fulfilling both the TatA and TatB functions. Furthermore, our results indicate that the structure of the amino-terminal domain of TatA is decisive for whether or not TatB is required.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3426-32
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Isolation and characterization of bifunctional Escherichia coli TatA mutant proteins that allow efficient tat-dependent protein translocation in the absence of TatB.
pubmed:affiliation
Institut für Biotechnologie 1, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't