Evolution of Aromatic beta-Glucoside Utilization by Successive Mutational Steps in Escherichia coli

Zangoui, Parisa and Vashishtha, Kartika and Mahadevan, Subramony (2015) Evolution of Aromatic beta-Glucoside Utilization by Successive Mutational Steps in Escherichia coli. In: JOURNAL OF BACTERIOLOGY, 197 (4). pp. 710-716.

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Abstract

The bglA gene of Escherichia coli encodes phospho-beta-glucosidase A capable of hydrolyzing the plant-derived aromatic beta-glucoside arbutin. We report that the sequential accumulation of mutations in bglA can confer the ability to hydrolyze the related aromatic beta-glucosides esculin and salicin in two steps. In the first step, esculin hydrolysis is achieved through the acquisition of a four-nucleotide insertion within the promoter of the bglA gene, resulting in enhanced steady-state levels of the bglA transcript. In the second step, hydrolysis of salicin is achieved through the acquisition of a point mutation within the bglA structural gene close to the active site without the loss of the original catabolic activity against arbutin. These studies underscore the ability of microorganisms to evolve additional metabolic capabilities by mutational modification of preexisting genetic systems under selection pressure, thereby expanding their repertoire of utilizable substrates.

Item Type:	Journal Article
Publication:	JOURNAL OF BACTERIOLOGY
Publisher:	AMER SOC MICROBIOLOGY
Additional Information:	Copy right for this article belongs to the AMER SOC MICROBIOLOGY, 1752 N ST NW, WASHINGTON, DC 20036-2904 USA
Department/Centre:	Division of Biological Sciences > Molecular Reproduction, Development & Genetics
Date Deposited:	04 Mar 2015 12:39
Last Modified:	04 Mar 2015 12:39
URI:	http://eprints.iisc.ac.in/id/eprint/50982

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