Search Results

You searched for all publications:

with publication states 'Published (Approved)'

Search Again...

These results only include publications that have been reviewed and processed by Diamond Light Source. To also view papers that have not yet been processed click here.

You can use the folder icon under Actions to collate papers as required. You can then click on View Folder in the left-hand navigation to review and/or download your folder.

Exact matches
Related results

3 items found (0 items not approved), displaying all items.1

Instruments / Technical Area	Publication Details	Published
Krios I-Titan Krios I at Diamond	Mechanism of membrane-tethered mitochondrial protein synthesis Yuzuru Itoh , Juni Andrell , Austin Choi , Uwe Richter , Priyanka Maiti , Robert B. Best , Antoni Barrientos , Brendan J. Battersby , Alexey Amunts Science 371, 846 - 849 DOI: 10.1126/science.abe0763 Diamond Proposal Number(s): [19823] Show Abstract ▼ Abstract: Mitochondrial ribosomes (mitoribosomes) are tethered to the mitochondrial inner membrane to facilitate the cotranslational membrane insertion of the synthesized proteins. We report cryo–electron microscopy structures of human mitoribosomes with nascent polypeptide, bound to the insertase oxidase assembly 1–like (OXA1L) through three distinct contact sites. OXA1L binding is correlated with a series of conformational changes in the mitoribosomal large subunit that catalyze the delivery of newly synthesized polypeptides. The mechanism relies on the folding of mL45 inside the exit tunnel, forming two specific constriction sites that would limit helix formation of the nascent chain. A gap is formed between the exit and the membrane, making the newly synthesized proteins accessible. Our data elucidate the basis by which mitoribosomes interact with the OXA1L insertase to couple protein synthesis and membrane delivery.	Feb 2021
	Crystal Structure of the Acid Induced Arginine Decarboxylase from Escherichia coli: Reversible Decamer Assembly Controls Enzyme Activity Juni Andrell , Matthew Hicks , Tracy Palmer , Liz Carpenter , So Iwata , Megan Maher Biochemistry DOI: 10.1139/O09-182 PMID: 20453931 Diamond Proposal Number(s): [316] Show Abstract ▼ Abstract: Enteric bacteria such as Escherichia coli have acquired a wide array of acid stress response systems to counteract the extreme acidity encountered when invading the host's digestive or urinary tracts. These acid stress response systems are both enzyme and chaperone based. The 3 main enzyme-based acid resistance pathways are glutamate-, arginine-, and lysine-decarboxylase pathways. They are under a complex regulatory network allowing the bacteria to fine tune its response to the external environment. HdeA and HdeB are the main chaperones involved in acid stress response. The decarboxylase systems are also found in Vibrio cholera, Vibrio vulnifus, Shigella flexneri. and Salmonella typhimurium, although some differences exist in their functional mechanism and regulation.	Mar 2009
NONE-No attached Diamond beamline	Thioredoxin A active-site mutants form mixed disulfide dimers that resemble enzyme-substrate reaction intermediates. Thijs R. H. M. Kouwen , Rianne Schrijver , Jean-yves F. Dubois , Megan J. Maher , Elizabeth P. Carpenter , Juni Andrell , So Iwata , Jan Maarten Van Dijl Journal Of Molecular Biology 379 (3), 520-34 DOI: 10.1016/j.jmb.2008.03.077 PMID: 18455736 Show Abstract ▼ Abstract: Thioredoxin functions in nearly all organisms as the major thiol-disulfide oxidoreductase within the cytosol. Its prime purpose is to maintain cysteine-containing proteins in the reduced state by converting intramolecular disulfide bonds into dithiols in a disulfide exchange reaction. Thioredoxin has been reported to contribute to a wide variety of physiological functions by interacting with specific sets of substrates in different cell types. To investigate the function of the essential thioredoxin A (TrxA) in the low-GC Gram-positive bacterium Bacillus subtilis, we purified wild-type TrxA and three mutant TrxA proteins that lack either one or both of the two cysteine residues in the CxxC active site. The pure proteins were used for substrate-binding studies known as "mixed disulfide fishing" in which covalent disulfide-bonded reaction intermediates can be visualized. An unprecedented finding is that both active-site cysteine residues can form mixed disulfides with substrate proteins when the other active-site cysteine is absent, but only the N-terminal active-site cysteine forms stable interactions. A second novelty is that both single-cysteine mutant TrxA proteins form stable homodimers due to thiol oxidation of the remaining active-site cysteine residue. To investigate whether these dimers resemble mixed enzyme-substrate disulfides, the structure of the most abundant dimer, C32S, was characterized by X-ray crystallography. This yielded a high-resolution (1.5A) X-ray crystallographic structure of a thioredoxin homodimer from a low-GC Gram-positive bacterium. The C32S TrxA dimer can be regarded as a mixed disulfide reaction intermediate of thioredoxin, which reveals the diversity of thioredoxin/substrate-binding modes.	Jun 2008

Publications Database

Search Results

You searched for all publications:

Search Again...

Subject Areas (check all that apply) select all

Instruments used to collect data (check all that apply) select all

Collaborations involved (check all that apply) select all

Diamond Offline Facilities used

Relevant Technical Areas (check all that apply) select all

Menu for Anonymous User