1urp
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D-RIBOSE-BINDING PROTEIN FROM ESCHERICHIA COLI
OverviewOverview
Conformational changes are necessary for the function of bacterial, periplasmic receptors in chemotaxis and transport. Such changes allow, entry and exit of ligand, and enable the correct interaction of the, ligand-bound proteins with the membrane components of each system. Three, open, ligand-free forms of the Escherichia coli ribose-binding protein, were observed here by X-ray crystallographic studies. They are opened by, 43 degrees, 50 degrees and 64 degrees with respect to the ligand-bound, protein reported previously. The three open forms are not distinct, but, show a clear relationship to each other. All are the product of a similar, opening motion, and are stabilized by a new, almost identical packing, interface between the domains. The changes are generated by similar bond, rotations, although some differences in the three hinge segments are, needed to accommodate the various structural scenarios. Some local, repacking also occurs as interdomain contacts are lost. The least open (43, degrees) form is probably the dominant one in solution under normal, conditions, although a mixture of species seems likely. The open and, closed forms have distinct surfaces in the regions known to be important, in chemotaxis and transport, which will differentiate their interactions, with the membrane components. It seems certain that the conformational, path that links the forms described here is that followed during ligand, retrieval, and in ligand release into the membrane-bound permease system.
About this StructureAbout this Structure
1URP is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
Multiple open forms of ribose-binding protein trace the path of its conformational change., Bjorkman AJ, Mowbray SL, J Mol Biol. 1998 Jun 12;279(3):651-64. PMID:9641984
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