6ali

Solution NMR structure of a putative thioredoxin (ECH_0218) in the oxidized state from Ehrlichia chaffeensis, the etiological agent responsible for human monocytic ehrlichiosis. Seattle Structural Genomics Center for Infectious Disease target EhchA.00546.a

spinqualitylabelsall models 6ali Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6ali is a 1 chain structure with sequence from Ehrlichia chaffeensis str. Arkansas. This structure supersedes the now removed PDB entry 2mod. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q2GHP2_EHRCR Publication Abstract from PubMed Thioredoxins are small ubiquitous proteins that participate in a diverse variety of redox reactions via the reversible oxidation of two cysteine thiol groups in a structurally conserved active site. Here, the NMR solution structures of a reduced and oxidized thioredoxin from Ehrlichia chaffeensis (Ec-Trx, ECH_0218), the etiological agent responsible for human monocytic ehrlichiosis, are described. The overall topology of the calculated structures is similar in both redox states and is similar to those of other thioredoxins: a five-stranded, mixed beta-sheet (beta1-beta3-beta2-beta4-beta5) surrounded by four alpha-helices. Unlike other thioredoxins studied by NMR in both redox states, the (1)H-(15)N HSQC spectrum of reduced Ec-Trx was missing eight additional amide cross peaks relative to the spectrum of oxidized Ec-Trx. These missing amides correspond to residues Cys35-Glu39 in the active-site-containing helix (alpha2) and Ser72-Ile75 in a loop near the active site, and suggest a change in backbone dynamics on the millisecond-to-microsecond timescale associated with the breakage of an intramolecular Cys32-Cys35 disulfide bond in a thioredoxin. A consequence of the missing amide resonances is the absence of observable or unambiguous NOEs to provide the distance restraints necessary to define the N-terminal end of the alpha-helix containing the CPGC active site in the reduced state. This region adopts a well defined alpha-helical structure in other reported reduced thioredoxin structures, is mostly helical in oxidized Ec-Trx and CD studies of Ec-Trx in both redox states suggests there is no significant difference in the secondary structure of the protein. The NMR solution structure of reduced Ec-Trx illustrates that the absence of canonical structure in a region of a protein may be owing to unfavorable dynamics prohibiting NOE observations or unambiguous NOE assignments. Solution NMR structures of oxidized and reduced Ehrlichia chaffeensis thioredoxin: NMR-invisible structure owing to backbone dynamics.,Buchko GW, Hewitt SN, Van Voorhis WC, Myler PJ Acta Crystallogr F Struct Biol Commun. 2018 Jan 1;74(Pt 1):46-56. doi:, 10.1107/S2053230X1701799X. Epub 2018 Jan 1. PMID:29372907 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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