Linked Life Data

16904687

Source:http://linkedlifedata.com/resource/pubmed/id/16904687

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2006-8-28
pubmed:databankReference
pubmed:abstractText
Periplasmic binding proteins (PBPs) comprise a protein superfamily that is involved in prokaryotic solute transport and chemotaxis. These proteins have been used to engineer reagentless biosensors to detect natural or non-natural ligands. There is considerable interest in obtaining very stable members of this superfamily from thermophilic bacteria to use as robust engineerable parts in biosensor development. Analysis of the recently determined genome sequence of Thermus thermophilus revealed the presence of more than 30 putative PBPs in this thermophile. One of these is annotated as a glucose binding protein (GBP) based on its genetic linkage to genes that are homologous to an ATP-binding cassette glucose transport system, although the PBP sequence is homologous to periplasmic maltose binding proteins (MBPs). Here we present the cloning, over-expression, characterization of cognate ligands, and determination of the X-ray crystal structure of this gene product. We find that it is a very stable (apo-protein Tm value is 100(+/- 2) degrees C; complexes 106(+/- 3) degrees C and 111(+/- 1) degrees C for glucose and galactose, respectively) glucose (Kd value is 0.08(+/- 0.03) microM) and galactose (Kd value is 0.94(+/- 0.04) microM) binding protein. Determination of the X-ray crystal structure revealed that this T. thermophilus glucose binding protein (ttGBP) is structurally homologous to MBPs rather than other GBPs. The di or tri-saccharide ligands in MBPs are accommodated in long relatively shallow grooves. In the ttGBP binding site, this groove is partially filled by two loops and an alpha-helix, which create a buried binding site that allows binding of only monosaccharides. Comparison of ttGBP and MBP provides a clear example of structural adaptations by which the size of ligand binding sites can be controlled in the PBP super family.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
362
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
259-70
pubmed:dateRevised
2011-6-30
pubmed:meshHeading
pubmed-meshheading:16904687-Amino Acid Sequence, pubmed-meshheading:16904687-Bacterial Proteins, pubmed-meshheading:16904687-Binding Sites, pubmed-meshheading:16904687-Carrier Proteins, pubmed-meshheading:16904687-Crystallography, X-Ray, pubmed-meshheading:16904687-Disaccharides, pubmed-meshheading:16904687-Glucose, pubmed-meshheading:16904687-Hydrogen Bonding, pubmed-meshheading:16904687-Ligands, pubmed-meshheading:16904687-Maltose-Binding Proteins, pubmed-meshheading:16904687-Models, Molecular, pubmed-meshheading:16904687-Molecular Sequence Data, pubmed-meshheading:16904687-Monosaccharides, pubmed-meshheading:16904687-Periplasmic Binding Proteins, pubmed-meshheading:16904687-Protein Binding, pubmed-meshheading:16904687-Protein Denaturation, pubmed-meshheading:16904687-Protein Structure, Tertiary, pubmed-meshheading:16904687-Sequence Alignment, pubmed-meshheading:16904687-Thermus thermophilus
pubmed:year
2006
pubmed:articleTitle
The crystal structure of a thermophilic glucose binding protein reveals adaptations that interconvert mono and di-saccharide binding sites.
pubmed:affiliation
The Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural