Linked Life Data

11022003

Source:http://linkedlifedata.com/resource/pubmed/id/11022003

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2000-11-13
pubmed:abstractText
The alphavirus RNA polymerase, nsP4, invariably has a Tyr residue at the N-terminus. Previously we reported that the N-terminal Tyr residue of nsP4 of Sindbis virus, the type species of the genus Alphavirus, can be substituted with Phe, Trp, or His without altering the wild-type phenotype in cultured cells but that other substitutions tested, except for Met, were lethal or quasilethal. Here we report the identification of two suppressor mutations in nsP4 (Glu-191 to Leu and Glu-315 to Gly, Val, or Lys) and one in nsP1 (Thr-349 to Lys) that allow nsP4 with nonaromatic amino acids at the N-terminus to function at 30 degrees C. The suppressor mutation at nsP4 Glu-315 occurred most frequently. All three suppressor mutations suppressed the effects of Ala, Arg, or Leu at the N-terminus of nsP4 with almost equal efficiency and thus the effect of the suppressing mutation is independent of the nsP4 N-terminal residue. Reconstructed mutants containing nsP1-T349K or nsP4-E315G combined with Ala-nsP4 had a defect in minus-strand RNA synthesis at 40 degrees C. A double mutant containing nsP4-Q191L combined with Ala-nsP4 was unstable and could not be tested for RNA synthesis because it reverted to temperature-independence too rapidly. Combinations of nsP1-T349K or nsP4-E315G with Leu, Arg, His, or any aromatic amino acid at the N-terminus of nsP4 also made the mutant viruses temperature sensitive. The results from this study and from a previous report on the shutoff of minus-strand RNA synthesis at 40 degrees C with the nsP1-A348T mutation in ts11 suggests that the N-terminus nsP4 interacts with nsP1 during initiation of minus-strand RNA synthesis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0042-6822
pubmed:author
pubmed:copyrightInfo
Copyright 2000 Academic Press.
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
148-60
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Suppressor mutations that allow sindbis virus RNA polymerase to function with nonaromatic amino acids at the N-terminus: evidence for interaction between nsP1 and nsP4 in minus-strand RNA synthesis.
pubmed:affiliation
Division of Biology 156-29, California Institute of Technology, Pasadena, California 91125, USA. shirako@ims.u-tokyo.ac.jp
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.