sup 19 F NMR studies of the D-galactose chemosensory receptor. (1) Sugar binding yields a global structural change

Journal Article · Tue Apr 30 00:00:00 EDT 1991 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00231a021· OSTI ID:5397989

Luck, L A; Falke, J J ^[1]

---

1. Univ. of Colorado, Boulder (USA)

The Escherichia coli D-galactose and D-glucose receptor is an aqueous sugar-binding protein and the first component in the distinct chemosensory and transport pathways for these sugars. Activation of the receptor occurs when the sugar binds and induces a conformational change, which in turn enable docking to specific membrane proteins. Only the structure of the activated receptor containing bound D-glucose is known. To investigate the sugar-induced structural change, the authors have used {sup 19}F NMR to probe 12 sites widely distributed in the receptor molecule. Five sites are tryptophan positions probed by incorporation of 5-fluorotryptophan; the resulting {sup 19}F NMR resonances were assigned by site-directed mutagenesis. The other seven sites are phenylalanine positions probed by incorporation of 3-fluorophenylaline. Sugar binding to the substrate binding cleft was observed to trigger a global structural change detected via {sup 19}F NMR frequency shifts at 10 of the 12 labeled sites. The results are consistent with a model in which multiple secondary structural elements, known to extend between the substrate cleft and the protein surface, undergo shifts in their average positions upon sugar binding to the cleft. Such structural coupling provides a mechanism by which sugar binding to the substrate cleft can cause structural changes at one or more docking sites on the receptor surface.

• OSTI ID: 5397989
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 30:17; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ALDEHYDES
AMINO ACIDS
AROMATICS
AZAARENES
AZOLES
BACTERIA
CARBOHYDRATES
CARBOXYLIC ACIDS
ESCHERICHIA COLI
FLUORINE 19
FLUORINE ISOTOPES
GALACTOSE
GLUCOSE
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HEXOSES
INDOLES
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MEMBRANE PROTEINS
MEMBRANE TRANSPORT
MICROORGANISMS
MOLECULAR STRUCTURE
MONOSACCHARIDES
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PROTEINS
PYRROLES
RECEPTORS
RESONANCE
SACCHARIDES
STABLE ISOTOPES
TRYPTOPHAN