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

J Basic Microbiol

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.

Published: June 2018

As of date the two temperature sensitive mutations isolated in pheST operon include pheS5 (G →A ) and pheT354. Recently, we reported that G 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 →A ) transition mutation as present in the classical pheS5 mutant. Most unexpectedly, the four pheT mutants isolated harbored the same G →A transition, a mutation which is hitherto unreported. Since all the four pheT mutants were defined by the same G →A base change, we believe that getting other mutations could be hard hitting and therefore it is proposed that G itself could be a "hot spot" for emergence of Ts mutations in pheT and similarly G itself could be a "hot spot" for Ts lesions in pheS. These results clearly imply a vital role for Glutamic acid (Glu ) of PheT and reinforce criticality of Glycine (Gly ) of PheS in the thermal stability of PheRS enzyme.

Download full-text PDF

Source
http://dx.doi.org/10.1002/jobm.201700645DOI Listing

Publication Analysis

Top Keywords

glu phet
8
thermal stability
8
phers enzyme
8
temperature sensitive
8
mutants isolated
8
phes phet
8
lesions phes
8
harbored →a
8
→a transition
8
transition mutation
8

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!