5LQ4

The Structure of ThcOx, the First Oxidase Protein from the Cyanobactin Pathways

5LQ4 の概要

• エントリーDOI: 10.2210/pdb5lq4/pdb
• 分子名称: CyaGox, FLAVIN MONONUCLEOTIDE, ... (4 entities in total)
• 機能のキーワード: cyanobactins oxidase s-sad ripps, oxidoreductase
• 由来する生物種: Cyanothece sp. (strain PCC 7425 / ATCC 29141); 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 106223.52

構造登録者

Bent, A.F.,Wagner, A.,Naismith, J.H. (登録日: 2016-08-16, 公開日: 2016-11-09, 最終更新日: 2024-05-08)

主引用文献

Bent, A.F.,Mann, G.,Houssen, W.E.,Mykhaylyk, V.,Duman, R.,Thomas, L.,Jaspars, M.,Wagner, A.,Naismith, J.H.
Structure of the cyanobactin oxidase ThcOx from Cyanothece sp. PCC 7425, the first structure to be solved at Diamond Light Source beamline I23 by means of S-SAD.
Acta Crystallogr D Struct Biol, 72:1174-1180, 2016

PubMed Abstract: Determination of protein crystal structures requires that the phases are derived independently of the observed measurement of diffraction intensities. Many techniques have been developed to obtain phases, including heavy-atom substitution, molecular replacement and substitution during protein expression of the amino acid methionine with selenomethionine. Although the use of selenium-containing methionine has transformed the experimental determination of phases it is not always possible, either because the variant protein cannot be produced or does not crystallize. Phasing of structures by measuring the anomalous diffraction from S atoms could in theory be almost universal since almost all proteins contain methionine or cysteine. Indeed, many structures have been solved by the so-called native sulfur single-wavelength anomalous diffraction (S-SAD) phasing method. However, the anomalous effect is weak at the wavelengths where data are normally recorded (between 1 and 2 Å) and this limits the potential of this method to well diffracting crystals. Longer wavelengths increase the strength of the anomalous signal but at the cost of increasing air absorption and scatter, which degrade the precision of the anomalous measurement, consequently hindering phase determination. A new instrument, the long-wavelength beamline I23 at Diamond Light Source, was designed to work at significantly longer wavelengths compared with standard synchrotron beamlines in order to open up the native S-SAD method to projects of increasing complexity. Here, the first novel structure, that of the oxidase domain involved in the production of the natural product patellamide, solved on this beamline is reported using data collected to a resolution of 3.15 Å at a wavelength of 3.1 Å. The oxidase is an example of a protein that does not crystallize as the selenium variant and for which no suitable homology model for molecular replacement was available. Initial attempts collecting anomalous diffraction data for native sulfur phasing on a standard macromolecular crystallography beamline using a wavelength of 1.77 Å did not yield a structure. The new beamline thus has the potential to facilitate structure determination by native S-SAD phasing for what would previously have been regarded as very challenging cases with modestly diffracting crystals and low sulfur content.

PubMed: 27841750
DOI: 10.1107/S2059798316015850

実験手法

X-RAY DIFFRACTION (2.65 Å)