5x04

12:0-ACP thioesterase from Umbellularia californica

spinqualitylabelsall models 5x04, resolution 2.43Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5x04 is a 2 chain structure with sequence from Umbellularia californica. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.43Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function FATB_UMBCA Plays an essential role in chain termination during de novo fatty acid synthesis. High thioesterase activity for lauroyl-ACP versus other acyl-ACPs. Publication Abstract from PubMed Acyl-ACP thioesterase (TE) catalyzes the hydrolysis of thioester bonds during type II fatty acid synthesis and directly determines fatty acid chain length. Most TEs are responsible for recognition of 16:0 and 18:1 substrates, while specific TEs interrupt acyl-ACP elongation at C8-C14. However, the acyl selection mechanism of TE has not been thoroughly elucidated to date. In this study, the crystal structure of the C12-specific thioesterase FatB from Umbellularia californica, which consists of two independent hotdog domains, was determined. An uncanonical Asp-His-Glu catalytic network was identified on the C-terminal hotdog domain, whereas the substrate binding pocket was determined to be on the N-terminal hotdog domain. Moreover, we elucidated UcFatB's substrate selection mechanism, which is accommodated by several unconservative amino acids on the beta5, beta2, and beta4 sheets and enclosed by T137 on the alpha1 helix. On this basis, the C12-specific TE was rationally redesigned toward C14 selectivity by tuning the substrate binding pocket capacity. The T137G mutant demonstrated comparative relative activity on C14 substrates compared to C12 substrates in vitro. Furthermore, the reconstructed UcFatB_T137G achieved C14 fatty acid content up to 40% in contrast to 10% C14 from the wild type in engineered E. coli cells. The unraveled substrate selection mechanism of TE provides a new strategy for tailoring fatty acid synthesis. Structural Insight into Acyl-ACP Thioesterase toward Substrate Specificity Design.,Feng Y, Wang Y, Liu J, Liu Y, Cao X, Xue S ACS Chem Biol. 2017 Nov 17;12(11):2830-2836. doi: 10.1021/acschembio.7b00641., Epub 2017 Oct 16. PMID:28991437 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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