Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2002-7-30
pubmed:abstractText
The tetracycline resistance proteins (TetA) of gram-negative bacteria are secondary active transport proteins that contain buried charged amino acids that are important for tetracycline transport. Earlier studies have shown that insertion of TetA proteins into the cytoplasmic membrane is mediated by helical hairpin pairs of transmembrane (TM) segments. However, whether helical hairpins direct spontaneous insertion of TetA or are required instead for its interaction with the cellular secretion (Sec) machinery is unknown. To gain insight into how TetA proteins are inserted into the membrane, we have investigated how tolerant the class C TetA protein encoded by plasmid pBR322 is to placement of charged residues in TM segments. The results show that the great majority of charge substitutions do not interfere with insertion even when placed at locations that cannot be shielded internally within helical hairpins. The only mutations that frequently block insertion are proline substitutions, which may interfere with helical hairpin folding. The ability of TetA to broadly tolerate charge substitutions indicates that the Sec machinery assists in its insertion into the membrane. The results also demonstrate that it is feasible to engineer charged residues into the interior of TetA proteins for the purpose of structure-function analysis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0003-9861
pubmed:author
pubmed:copyrightInfo
Copyright 2002 Elsevier Science (USA).
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
404
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
317-25
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Mutational analysis of tetracycline resistance protein transmembrane segment insertion.
pubmed:affiliation
Department of Molecular Biology, University of Wyoming, P.O. Box 3944, Laramie, WY 82071-3944, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.