Simultaneous presence of fhs and purT genes is disadvantageous for the fitness of Escherichia coli growth

Aluri, Srinivas and Rex, Kervin and Varshney, Umesh (2015) Simultaneous presence of fhs and purT genes is disadvantageous for the fitness of Escherichia coli growth. In: FEMS MICROBIOLOGY LETTERS, 362 (14).

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Abstract

In bacteria, alternate mechanisms are known to synthesize N-10-formyltetrahydrofolate (N10-formyl-THF) and formyl glycinamide ribotide (fGAR), which are important in purine biosynthesis. In one of the mechanisms, a direct transfer of one carbon unit from formate allows Fhs to convert tetrahydrofolate to N-10-formyl-THF, and PurT to convert glycinamide ribotide (GAR) to fGAR. Our bioinformatics analysis of fhs and purT genes (encoding Fhs and PurT) showed that in a majority of bacteria (similar to 94%), their presence was mutually exclusive. A large number of organisms possessing fhs lacked purT and vice versa. The phenomenon is so penetrating that even within a genus (Bacillus) if a species possessed fhs it lacked purT and vice versa. To investigate physiological importance of this phenomenon, we used Escherichia coli, which naturally lacks fhs (and possesses purT) as model. We generated strains, which possessed fhs and purT genes in singles or together. Deletion of purT from E. coli in the presence or absence of fhs did not confer a detectable growth disadvantage in pure cultures. However, growth competition assays revealed that the strains possessing either of the single genes outcompeted those possessing both the genes suggesting that mutual exclusion of purT and fhs in organisms confers fitness advantage in mixed cultures.

Item Type:	Journal Article
Publication:	FEMS MICROBIOLOGY LETTERS
Publisher:	OXFORD UNIV PRESS
Additional Information:	Copy right for this article belongs to the OXFORD UNIV PRESS, GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND
Keywords:	anti-correlative presence of genes; growth fitness advantage; growth competitions
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	24 Sep 2015 06:29
Last Modified:	24 Sep 2015 06:29
URI:	http://eprints.iisc.ac.in/id/eprint/52408

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