1DMB

REFINED 1.8 ANGSTROMS STRUCTURE REVEALS THE MECHANISM OF BINDING OF A CYCLIC SUGAR, BETA-CYCLODEXTRIN, TO THE MALTODEXTRIN BINDING PROTEIN

Summary for 1DMB

• Entry DOI: 10.2210/pdb1dmb/pdb
• Related PRD ID: PRD_900012
• Descriptor: D-MALTODEXTRIN BINDING PROTEIN, Cycloheptakis-(1-4)-(alpha-D-glucopyranose) (3 entities in total)
• Functional Keywords: sugar transport
• Biological source: Escherichia coli
• Total number of polymer chains: 1
• Total formula weight: 41906.15

Authors

Sharff, A.J.,Quiocho, F.A. (deposition date: 1993-06-10, release date: 1993-10-31, Last modification date: 2024-02-07)

Primary citation

Sharff, A.J.,Rodseth, L.E.,Quiocho, F.A.
Refined 1.8-A structure reveals the mode of binding of beta-cyclodextrin to the maltodextrin binding protein.
Biochemistry, 32:10553-10559, 1993

PubMed Abstract: The maltodextrin binding protein from Escherichia coli serves as the initial receptor for both the active transport of and chemotaxis toward a range of linear maltose sugars. The X-ray structures of both the maltose-bound and sugar-free forms of the protein have been previously described [Spurlino, J. C., Lu, G.-Y., & Quiocho, F. A. (1991) J. Biol. Chem. 266, 5202-5219; Sharff, A. J., Rodseth, L. E., Spurlino, J. C., & Quocho, F. A. (1992) Biochemistry 31, 10657-10663]. The X-ray crystal structure of the maltodextrin binding protein complexed with cyclomaltoheptaose (beta-cyclodextrin) has been determined from a single crystal. The structure has been refined to a final R-value of 21% at 1.8-A resolution. Although not a physiological ligand for the maltodextrin binding protein, beta-cyclodextrin has been shown to bind with a Kd of the same order as those of the linear maltodextrin substrates. The observed structure shows that the complexed protein remains in the fully open conformation and is almost identical to the structure of the unliganded protein. The sugar sits in the open cleft with three glucosyl units bound to the C-domain at the base of the cleft, in a similar position to maltotriose, the most tightly bound ligand. The top of the ring is loosely bound to the upper edge of the cleft on the N-domain. The sugar makes a total of 94 productive interactions (of less than 4.0-A length) with the protein and with bound water molecules.(ABSTRACT TRUNCATED AT 250 WORDS)

PubMed: 8399200
DOI: 10.1021/bi00091a004

Experimental method

X-RAY DIFFRACTION (1.8 Å)