Disease relevance of leuX

• The leuX gene of Escherichia coli codes for a suppressor tRNA and forms a single gene operon containing its own promoter and Q-independent terminator [1].

High impact information on leuX

• The fim switch was shown to be switched off in leuX-derivatives of E. coli 536, but could be found in the on position when the codon-altered fimB gene was exchanged into the chromosome of these strains [2].
• Both pathogenicity islands, Pai I and Pai II, are incorporated into tRNA specific loci: Pai I is located in the tRNA gene for selenocysteine (selC), and Pai II is integrated in the leucine-specific tRNA locus leuX [3].
• The rare leucine-specific tRNA5(Leu), encoded by leuX, influences a number if properties including type 1 fimbria production, flagellation and motility, production of enterobactin and serum resistance, and is also necessary for full in vivo virulence [3].
• In order to determine the influence of the two tRNAs on the expression of these properties, the genes selC and leuX were cloned from the genome of strain 536 and then introduced into the mutant 536-21 [3].
• Sequence analysis of the PAI region junction sites revealed sequences of the leuX and selC loci specific for leucine and selenocysteine tRNAs [4].

Biological context of leuX

• An integrase with strong homology to the LEE O26 integrase was detected on the K-12 chromosome associated with the leuX tRNA locus at 97 min [5].
• The global impact of the presence or absence of the leuX-encoded tRNA on gene expression of the uropathogenic E. coli strain 536 was studied by proteome analysis [6].

Associations of leuX with chemical compounds

• While leuX transcription was unchanged or slightly up-regulated by an increase in growth temperature, osmolarity or ethanol concentration, that of leuV was reduced [7].

Other interactions of leuX

• Interestingly, the archetype E. coli K1 neonatal meningitis strain, strain RS218, has two copies of the dsdCXA genes for d-serine utilization at the argW and leuX islands [8].

References