Crystal structure of the hydroxylaminopurine resistance protein, YiiM, and its putative molybdenum cofactor-binding catalytic site
| Autor: | Wan Seok Song, Sung-il Yoon, Byeol Namgung, Jee-Hyeon Kim |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Stereochemistry lcsh:Medicine medicine.disease_cause Article Cofactor 03 medical and health sciences chemistry.chemical_compound Residue (chemistry) Oxidoreductase medicine lcsh:Science Escherichia coli chemistry.chemical_classification Multidisciplinary 030102 biochemistry & molecular biology biology lcsh:R Substrate (chemistry) biology.organism_classification 030104 developmental biology chemistry biology.protein lcsh:Q Molybdenum cofactor Bacteria Cysteine |
| Zdroj: | Scientific Reports, Vol 8, Iss 1, Pp 1-12 (2018) Scientific Reports |
| ISSN: | 2045-2322 |
| Popis: | The molybdenum cofactor (Moco) is a molybdenum-conjugated prosthetic group that is ubiquitously found in plants, animals, and bacteria. Moco is required for the nitrogen-reducing reaction of the Moco sulfurase C-terminal domain (MOSC) family. Despite the biological significance of MOSC proteins in the conversion of prodrugs and resistance against mutagens, their structural features and Moco-mediated catalysis mechanism have not been described in detail. YiiM is a MOSC protein that is involved in reducing mutagenic 6-N-hydroxylaminopurine to nontoxic adenine in bacteria. Here, we report two crystal structures of YiiM: one from Gram-positive Geobacillus stearothermophilus (gsYiiM) and the other from Gram-negative Escherichia coli (ecYiiM). Although gsYiiM and ecYiiM differ in oligomerization state and protein stability, both consist of three structural modules (a β-barrel and two α-helix bundles) and feature a cavity surrounded by the three modules. The cavity is characterized by positive electrostatic potentials and high sequence conservation. Moreover, the ecYiiM cavity houses a phosphate group, which emulates a part of Moco, and contains a highly reactive invariant cysteine residue. We thus propose that the cavity is the catalytic site where Moco binds and the substrate is reduced. Moreover, our comparative structural analysis highlights the common but distinct structural features of MOSC proteins. |
| Databáze: | OpenAIRE |
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