Linked Life Data

15807540

Source:http://linkedlifedata.com/resource/pubmed/id/15807540

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
14
pubmed:dateCreated
2005-4-5
pubmed:abstractText
All eight cysteine residues, C90, C94, C143, C147, C219, C325, C367, and C431, present in transmembrane domains of the Aspergillus nidulans NrtA nitrate transporter protein were altered individually by site-specific mutagenesis. The results indicate that six residues, C90, C147, C219, C325, C367, and C431, are not required for nitrate transport. Although alterations of C94 and C143 are less well tolerated, these residues are not mandatory and their possible role is discussed. A series of constructs, all completely devoid of cysteine residues, was generated to permit future cysteine-scanning mutagenesis. The optimum cysteine-less combination was identified as C90A, C94A, C143A, C147T, C219S, C325S, C367S, and C431S. This mutant combination yielded transformant strains with up to 40% of wild-type nitrate transport activity. Furthermore, the K(m) value and the level of protein expression were found to be similar to those of the wild-type. This cysteine-less vector should allow us to investigate in detail potentially interesting NrtA amino acids (e.g. identified from homology comparisons) which may be involved in transport, by altering these singly to cysteine and studying such residues by thiol chemistry.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5471-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Determination of the essentiality of the eight cysteine residues of the NrtA protein for high-affinity nitrate transport and the generation of a functional cysteine-less transporter.
pubmed:affiliation
School of Biology, University of St Andrews, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't