The YjgF/YER057c/UK114 family of proteins is conserved in all domains of life []. A phylogenetic analysis applied by Lambrecht et al.has divided the Rid family into a widely distributed archetypal RidA (YjgF) subfamily and seven other subfamilies (Rid1 to Rid7) that are largely confined to bacteria and often co-occur in the same organism with RidA and each other [].This entry represents part of the RidA subfamily. Its members include the mammalian endoribonuclease UK114, the yeast YER057C and the bacterial protein YjgF. However, this entry does not include RutC, which is represented in . YjgF contains the enamine/imine deaminase activity and can accelerate the release of ammonia from reactive enamine/imine intermediates of the pyridoxal 5'-phosphate-dependent threonine dehydratase (IlvA). Therefore, YjgF is also known as RidA (reactive intermediate/imine deaminase A) []. Although RidA subfamily members share protein and structure similarity, they may have different functions. For instance, rat ribonuclease UK114, also known as Hrsp12 or Psp1,is an endoribonuclease responsible for the inhibition of the translation by cleaving mRNA [, ]. Budding yeast YER057C (also known as Hmf1) is involved in maintenance of the mitochondrial genome [].
This entry represents a conserved site found towards the C-terminal of the YjgF family members. YjgF contains the enamine/imine deaminase activity and can accelerate the release of ammonia from reactive enamine/imine intermediates of the pyridoxal 5'-phosphate-dependent threonine dehydratase (IlvA). Therefore, YjgF is also known as RidA (reactive intermediate/imine deaminase A) []. The RidA family members are widely distributed in eubacteria, archaea and eukaryotes. Although they share protein sequences and structures similarity, they may have different functions. In this C-terminal domain, the highly conserved Arg107 of human hp14.5 (also known as ribonuclease UK114) forms salt bridges with the carboxylate oxygens of benzoate [], while the corresponding Arg105 of Escherichia coli TdcF forms hydrogen bonds with the carboxylate oxygens of serine, threonine, and 2-oxobutanoate []. The conserved Tyr17 and Glu120 residues of E. coli TdcF have been suggested to play a role in substrate binding and positioning of a water molecule used for imine hydrolysis [].
The YjgF/YER057c/UK114 family (also known as the Rid family) of proteins is conserved in all domains of life []. A phylogenetic analysis applied by Lambrecht et al.has divided the Rid family into a widely distributed archetypal RidA (YjgF) subfamily and seven other subfamilies (Rid1 to Rid7) that are largely confined to bacteria and often co-occur in the same organism with RidA and each other []. Although the family members share high levels of protein sequence and structure similarity, their functions vary widely across different species []. Structurally, these proteins are homotrimers with clefts between the monomeric subunits that are proposed to have some functional relevance [, , ].This family includes: YjgF (also known as RidA or 2-iminobutanoate/2-iminopropanoate deaminase), which displays enamine/imine deaminase activity and can accelerate the release of ammonia from reactive enamine/imine intermediates of the pyridoxal 5'-phosphate-dependent threonine dehydratase (IlvA) [, ]the yeast growth inhibitor YER057c (protein HMF1) that appears to play a role in the regulation of metabolic pathways and cell differentiation []the mammalian 14.5kDa translational inhibitor protein UK114, also known as L-PSP (liver perchloric acid-soluble protein), with endoribonucleolytic activity that directly affects mRNA translation and can induce disaggregation of the reticulocyte polysomes into 80 S ribosomes []RutC from E. coli, which is essential for growth on uracil as sole nitrogen source and is thought to reduce aminoacrylate peracid to aminoacrylate []YabJ from B. subtilis, which is required for adenine-mediated repression of purine biosynthetic genes []
