Disease relevance of ffs

• Sequence comparisons, however, have identified (i) a gene in Escherichia coli (ffh) whose product is homologous to the 54-kilodalton subunit (SRP54) of SRP, and (ii) an RNA encoded by the ffs gene (4.5S RNA) that shares a conserved domain with the 7SL RNA of SRP [1].

High impact information on ffs

• The membrane protein assembly defective mutants contain a mutation in the secA operon and three mutations in the ffs gene, which encodes 4.5S RNA [2].
• An isosteric C293-G(74) base pair, but not a C292-G(75) pair, fully restored catalytic performance in vivo, as shown for processing of precursor 4.5S RNA [3].
• We measured the concentrations of both 4.5S RNA and Ffh protein under a variety of growth conditions and found that there were 400 molecules of 4.5S RNA per 10,000 ribosomes in wild-type cells and that the concentration of Ffh protein was one-fourth of that [4].
• Pulse-chase labeling experiments indicated that Ffh protein is unstable in cells carrying ffh on high-copy-number plasmids and that simultaneous overproduction of 4.5S RNA stabilizes Ffh protein [4].
• RESULTS: We have determined by multiple anomalous dispersion (MAD) with Lu(3+) the 2.7 A crystal structure of a 4.5S RNA fragment containing binding sites for both Ffh and EF-G [5].

Anatomical context of ffs

• BACKGROUND: Bacterial signal recognition particle (SRP), consisting of 4.5S RNA and Ffh protein, plays an essential role in targeting signal-peptide-containing proteins to the secretory apparatus in the cell membrane [5].

Regulatory relationships of ffs

• The mutant also shows elevated expression of heat shock proteins and accumulates insoluble proteins, especially at 42 degrees C. It was further observed that the temperature sensitivity of the ffh mutant was suppressed by overproduction of 4.5S RNA, the RNA component of the bacterial SRP, by stabilizing the thermolabile protein [6].

References