3 research outputs found
An insight into the origin and functional evolution of bacterial aromatic ring-hydroxylating oxygenases
<div><p>Bacterial aromatic ring-hydroxylating oxygenases (RHOs) are multicomponent enzyme systems which have potential utility in bioremediation of aromatic compounds in the environment. To cope with the enormous diversity of aromatic compounds in the environment, this enzyme family has evolved remarkably exhibiting broad substrate specificity. RHOs are multicomponent enzymes comprising of a homo- or hetero-multimeric terminal oxygenase and one or more electron transport (ET) protein(s). The present study attempts in depicting the evolutionary scenarios that might have occurred during the evolution of RHOs, by analyzing a set of available sequences including those obtained from complete genomes. A modified classification scheme identifying four new RHO types has been suggested on the basis of their evolutionary and functional behaviours, in relation to structural configuration of substrates and preferred oxygenation site(s). The present scheme emphasizes on the fact that the phylogenetic affiliation of RHOs is distributed among four distinct ‘Similarity classes’, independent of the constituent ET components. Similar combination of RHO components that was previously considered to be equivalent and classified together [Kweon et al., BMC Biochemistry 9, 11 (2008)] were found here in distinct similarity classes indicating the role of substrate-binding terminal oxygenase in guiding the evolution of RHOs irrespective of the nature of constituent ET components. Finally, a model for evolution of the multicomponent RHO enzyme system has been proposed, beginning from genesis of the terminal oxygenase components followed by recruitment of constituent ET components, finally evolving into various ‘extant’ RHO types.</p>
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Biological Safety Assessment of Mutant Variant of <i>Allium sativum</i> Leaf Agglutinin (mASAL), a Novel Antifungal Protein for Future Transgenic Application
Genetic engineering has established
itself to be an important tool
for crop improvement. Despite the success, there is always a risk
of food allergy induced by alien gene products. The present study
assessed the biosafety of mutant <i>Allium sativum</i> leaf
agglutinin (mASAL), a potent antifungal protein generated by site
directed mutagenesis of <i>Allium sativum</i> leaf agglutinin
(ASAL). mASAL was cloned in pET28a+ and expressed in <i>E. coli</i>, and the safety assessment was carried out according to the FAO/WHO
guideline (2001). Bioinformatics analysis, pepsin digestion, and thermal
stability assay showed the protein to be nonallergenic. Targeted sera
screening revealed no significant IgE affinity of mASAL. Furthermore,
mASAL sensitized Balb/c mice showed normal histopathology of lung
and gut tissue. All results indicated the least possibility of mASAL
being an allergen. Thus, mASAL appears to be a promising antifungal
candidate protein suitable for agronomical biotechnology
MOESM1 of Thermophilic bacteria are potential sources of novel Rieske non-heme iron oxygenases
Additional file 1. Additional tables