1zkb
From Proteopedia
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|ACTIVITY= | |ACTIVITY= | ||
|GENE= malE ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |GENE= malE ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1ziu|1ZIU]], [[1zjl|1ZJL]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1zkb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1zkb OCA], [http://www.ebi.ac.uk/pdbsum/1zkb PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1zkb RCSB]</span> | ||
}} | }} | ||
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[[Category: zinc binding mutant]] | [[Category: zinc binding mutant]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 01:37:50 2008'' |
Revision as of 22:37, 30 March 2008
| |||||||
| , resolution 2.20Å | |||||||
|---|---|---|---|---|---|---|---|
| Gene: | malE (Escherichia coli) | ||||||
| Related: | 1ZIU, 1ZJL
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Zinc-free Engineered maltose binding protein
Overview
Protein engineering was used previously to convert maltose-binding protein (MBP) into a zinc biosensor. Zn(2+) binding by the engineered MBP was thought to require a large conformational change from "open" to "closed", similar to that observed when maltose is bound by the wild-type protein. We show that although this re-designed MBP molecule binds Zn(2+) with high affinity as previously reported, it does not adopt a closed conformation in solution as assessed by small-angle X-ray scattering. High-resolution crystallographic studies of the engineered Zn(2+)-binding MBP molecule demonstrate that Zn(2+) is coordinated by residues on the N-terminal lobe only, and therefore Zn(2+) binding does not require the protein to adopt a fully closed conformation. Additional crystallographic studies indicate that this unexpected Zn(2+) binding site can also coordinate Cu(2+) and Ni(2+) with only subtle changes in the overall conformation of the protein. This work illustrates that the energetic barrier to domain closure, which normally functions to maintain MBP in an open concentration in the absence of ligand, is not easily overcome by protein design. A comparison to the mechanism of maltose-induced domain rearrangement is discussed.
About this Structure
1ZKB is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Structural studies of an engineered zinc biosensor reveal an unanticipated mode of zinc binding., Telmer PG, Shilton BH, J Mol Biol. 2005 Dec 9;354(4):829-40. Epub 2005 Oct 28. PMID:16288781
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