RESUMEN
A strain of Bacillus amyloliquefaciens (VCRC B483) exhibiting mosquito pupicidal, keratinase and antimicrobial activities was isolated from mangrove forest ecosystem of Andaman and Nicobar Islands. Molecular characterization of the strain showed the presence of lipopeptide encoding bmyC gene. Phylogenetic tree based on protein sequence of this gene exhibited homology with mycosubtilin synthetase of Bacilus atropheus and Iturin synthetase of Bacillus subtilis and B. amyloliquefaciens. This is the first report on the evolutionary conservation of amino acids concerned with the function and structure of bmyC protein of B. amyloliquefaciens. The presence of valine at the 1197th position in our strain was found to be unique and different from the existing strains of B. subtilis and B. amyloliquefaciens. Molecular modelling studies revealed significant changes in the structure of epimerization domain of the bmyC protein with A1197V variation. Crude metabolite of this strain exhibited antifungal activity against Fusarium sp. and Carvularia sp.
Asunto(s)
Antifúngicos/farmacología , Bacillus amyloliquefaciens/genética , Bacillus amyloliquefaciens/metabolismo , Culicidae/microbiología , Genes Bacterianos/genética , Péptidos/genética , Secuencia de Aminoácidos , Animales , Antifúngicos/metabolismo , Péptidos Catiónicos Antimicrobianos , Bacillus/enzimología , Bacillus/genética , Bacillus amyloliquefaciens/enzimología , Proteínas Bacterianas/genética , Proteínas Bacterianas/farmacología , Fusarium/efectos de los fármacos , Lipopéptidos/genética , Lipopéptidos/metabolismo , Modelos Moleculares , Complejos Multienzimáticos/genética , Complejos Multienzimáticos/farmacología , Péptidos/farmacología , Filogenia , Alineación de Secuencia , Homología de SecuenciaRESUMEN
Mutations in the glucokinase (GK) gene play a critical role in the establishment of type 2 diabetes. In our earlier study, R308K mutation in GK in a clinically proven type 2 diabetic patient showed, structural and functional variations that contributed immensely to the hyperglycemic condition. In the extension of this work, a cohort of 30 patients with established type 2 diabetic condition were chosen and the exons 10 and 11 of GK were PCR-amplified and sequenced. The sequence alignment showed A379S, D400Y, E300A, E395A, E395G, H380N, I348N, L301M, M298I, M381G, M402R, R308K, R394P, R397S, and S398R mutations in 12 different patients. The structural analysis of these mutated GKs, showed a variable number of ß-α-ß units, hairpins, ß-bulges, strands, helices, helix-helix interactions, ß-turns, and γ-turns along with the RMSD variations when compared to wild-type GK. Molecular modeling studies revealed that the substrate showed variable binding orientations and could not fit into the active site of these mutated structures; moreover, it was expelled out of the conformations. Therefore, these structural variations in GK due to mutations could be one of the strongest reasons for the hyperglycemic levels in these type 2 diabetic patients.