Glu 571 of PheT plays a pivotal role in the thermal stability of Escherichia coli PheRS enzyme.

Autor: Ashwin Sri Bala S; Department of Molecular Biology, School of Biological Sciences, Centre for Advanced Studies in Functional and Organismal Genomics, Madurai Kamaraj University (University with Potential for Excellence), Madurai, India., Madhumathi I; Department of Molecular Biology, School of Biological Sciences, Centre for Advanced Studies in Functional and Organismal Genomics, Madurai Kamaraj University (University with Potential for Excellence), Madurai, India., Vinodha S; Department of Molecular Biology, School of Biological Sciences, Centre for Advanced Studies in Functional and Organismal Genomics, Madurai Kamaraj University (University with Potential for Excellence), Madurai, India., Munavar MH; Department of Molecular Biology, School of Biological Sciences, Centre for Advanced Studies in Functional and Organismal Genomics, Madurai Kamaraj University (University with Potential for Excellence), Madurai, India.
Jazyk: angličtina
Zdroj: Journal of basic microbiology [J Basic Microbiol] 2018 Jun; Vol. 58 (6), pp. 475-491. Date of Electronic Publication: 2018 Apr 16.
DOI: 10.1002/jobm.201700645
Abstrakt: As of date the two temperature sensitive mutations isolated in pheST operon include pheS5 (G 293 →A 293 ) and pheT354. Recently, we reported that G 673 of pheS defines a hot spot for intragenic suppressors of pheS5. In this investigation, in 13 independent experiments, a collection of temperature sensitive mutants were isolated by localized mutagenesis. Complementation using clones bearing pheS + , pheT + , and pheS + T + indicated that 34 mutants could harbor lesion(s) in pheS and four could be in pheT and one mutant might be a double mutant. Surprisingly, all the 34 pheS mutants harbored the very same (G 293 →A 293 ) transition mutation as present in the classical pheS5 mutant. Most unexpectedly, the four pheT mutants isolated harbored the same G 1711 →A 1711 transition, a mutation which is hitherto unreported. Since all the four pheT mutants were defined by the same G 1711 →A 1711 base change, we believe that getting other mutations could be hard hitting and therefore it is proposed that G 1711 itself could be a "hot spot" for emergence of Ts mutations in pheT and similarly G 293 itself could be a "hot spot" for Ts lesions in pheS. These results clearly imply a vital role for Glutamic acid 571 (Glu 571 ) of PheT and reinforce criticality of Glycine 98 (Gly 98 ) of PheS in the thermal stability of PheRS enzyme.
(© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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