Linked Life Data

7017276

Source:http://linkedlifedata.com/resource/pubmed/id/7017276

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1981-8-10
pubmed:abstractText
Genetic evidence suggests that the high-affinity L-histidine transport in Salmonella typhimurium requires the participation of a periplasmic binding protein (histidine-binding protein J) and two other proteins (P and Q proteins). The histidine-binding protein J binds L-histidine as the first step in the high-affinity active transport of this amino acid across the cytoplasmic membrane. High-resolution proton nuclear magnetic resonance spectroscopy at 600 MHz is used to investigate the conformations of this protein in the absence and presence of substrate. Previous nuclear magnetic resonance results reported by this laboratory have shown that there are extensive spectral changes in this protein upon the addition of L-histidine. When resonances from individual amino acid residues of a protein can be resolved in the proton nuclear magnetic resonance spectrum, a great deal of detailed information about substrate-induced structural changes can be obtained. In order to gain a deeper insight into the nature of these structural changes, deuterated phenylalanine or tyrosine has been incorporated into the bacteria. Proton nuclear magnetic resonance spectra of selectively deuterated histidine-binding protein J were obtained and compared to the normal protein. Several of the proton resonances have been assigned to the various aromatic amino acid residues of this protein. A model for the high-affinity transport of L-histidine across the cytoplasmic membrane of S typhimurium is proposed. This model, which is a version of the pore model, assumes that both P and Q proteins are membrane-bound and that the interface between these two proteins forms the channel for the passage of substrate. The histidine-binding protein J serves as the "key" for the opening of the channel for the passage of L-histidine. In the absence of substrate, this channel or gate is closed owing to a lack of appropriate interactions among these three proteins. The channel can be opened upon receiving a specific signal from the "key"; namely, the substrate-induced conformational changes in the histidine-binding protein J molecule. This model is consistent with available experimental evidence for the high-affinity transport of L-histidine across the cytoplasmic membrane of S typhimurium.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0091-7419
pubmed:author
pubmed:issnType
Print
pubmed:volume
13
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
131-45
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1980
pubmed:articleTitle
A proton nuclear magnetic resonance investigation of histidine-binding protein J of Salmonella typhimurium: a model for transport of L-histidine across cytoplasmic membrane.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.