2k0y

The actinorhodin apo acyl carrier protein from S. coelicolor

spinqualitylabelsall models 2k0y, 20 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2k0y is a 1 chain structure with sequence from Streptomyces coelicolor. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 1af8, 2af8 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [ACPX_STRCO] Acyl carrier protein. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The actinorhodin (act) synthase acyl carrier protein (ACP) from Streptomyces coelicolor plays a central role in polyketide biosynthesis. Polyketide intermediates are bound to the free sulfhydryl group of a phosphopantetheine arm that is covalently linked to a conserved serine residue in the holo form of the ACP. The solution NMR structures of both the apo and holo forms of the ACP are reported, which represents the first high resolution comparison of these two forms of an ACP. Ensembles of twenty apo and holo structures were calculated and yielded atomic root mean square deviations of well-ordered backbone atoms to the average coordinates of 0.37 and 0.42 A, respectively. Three restraints defining the protein to the phosphopantetheine interface were identified. Comparison of the apo and holo forms revealed previously undetected conformational changes. Helix III moved towards helix II (contraction of the ACP), and Leu43 on helix II subtly switched from being solvent exposed to forming intramolecular interactions with the newly added phosphopantetheine side chain. Tryptophan fluorescence and S. coelicolor fatty acid synthase (FAS) holo-synthase (ACPS) assays indicated that apo-ACP has a twofold higher affinity (K(d) of 1.1 muM) than holo-ACP (K(d) of 2.1 muM) for ACPS. Site-directed mutagenesis of Leu43 and Asp62 revealed that both mutations affect binding, but have differential affects on modification by ACPS. Leu43 mutations in particular strongly modulate binding affinity for ACPS. Comparison of apo- and holo-ACP structures with known models of the Bacillus subtilis FAS ACP-holo-acyl carrier protein synthase (ACPS) complex suggests that conformational modulation of helix II and III between apo- and holo-ACP could play a role in dissociation of the ACP-ACPS complex. An ACP Structural Switch: Conformational Differences between the Apo and Holo Forms of the Actinorhodin Polyketide Synthase Acyl Carrier Protein.,Evans SE, Williams C, Arthur CJ, Burston SG, Simpson TJ, Crosby J, Crump MP Chembiochem. 2008 Sep 3. PMID:18770515 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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