2flh
From Proteopedia
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Crystal structure of cytokinin-specific binding protein from mung bean in complex with cytokinin
Overview
The cytosolic fraction of Vigna radiata contains a 17-kD protein that, binds plant hormones from the cytokinin group, such as zeatin. Using, recombinant protein and isothermal titration calorimetry as well as, fluorescence measurements coupled with ligand displacement, we have, reexamined the K(d) values and show them to range from approximately, 10(-6) M (for 4PU30) to 10(-4) M (for zeatin) for 1:1 stoichiometry, complexes. In addition, we have crystallized this cytokinin-specific, binding protein (Vr CSBP) in complex with zeatin and refined the structure, to 1.2 A resolution. Structurally, Vr CSBP is similar to plant, pathogenesis-related class 10 (PR-10) proteins, despite low sequence, identity (<20%). This unusual fold conservation reinforces the notion that, classic PR-10 proteins have evolved to bind small-molecule ligands. The, fold consists of an antiparallel beta-sheet wrapped around a C-terminal, alpha-helix, with two short alpha-helices closing a cavity formed within, the protein core. In each of the four independent CSBP molecules, there is, a zeatin ligand located deep in the cavity with conserved conformation and, protein-ligand interactions. In three cases, an additional zeatin molecule, is found in variable orientation but with excellent definition in electron, density, which plugs the entrance to the binding pocket, sealing the inner, molecule from contact with bulk solvent.
About this Structure
2FLH is a Single protein structure of sequence from Vigna radiata with and as ligands. Full crystallographic information is available from OCA.
Reference
Crystal structure of Vigna radiata cytokinin-specific binding protein in complex with zeatin., Pasternak O, Bujacz GD, Fujimoto Y, Hashimoto Y, Jelen F, Otlewski J, Sikorski MM, Jaskolski M, Plant Cell. 2006 Oct;18(10):2622-34. Epub 2006 Sep 22. PMID:16998071
Page seeded by OCA on Tue Jan 29 19:39:21 2008
