Disease relevance of tRNA-Val

• Solvent exchange rates of selected protons were measured by NMR saturation recovery for E. coli tRNAVal, E. colifMet and yeast tRNAPhe, at temperatures from 20 to 40 degrees C, in the presence of 0.12M Na+ and various levels of added spermidine. tRNAVal was also studied with added Mg++ [1].
• Considering the fact that the 3'-terminal sequence of TYM virus RNA has only a few points of resemblance to a tRNA sequence, we propose that there are some structural motifs found in both tRNAVal and TYM virus RNA which are brought in a similar spatial arrangement recognized by valyl-tRNA synthetase [2].

High impact information on tRNA-Val

• From mutagenesis of the ATG-139 we conclude that the presequence specifically targets the cytoplasmically synthesized mitochondrial valyl-tRNA synthetase to the mitochondrial outer membrane and prevents binding of the enzyme core to cytoplasmic tRNAVal [3].
• The absence of essential recognition nucleotides in the acceptor helix was confirmed by converting E.coli tRNAAlaand yeast tRNAPhe, whose acceptor stem sequences differ significantly from that of tRNAVal, to efficient valine acceptors [4].
• The negative effects of G:U base pairs are strongly correlated with changes in helix structure in the vicinity of position 4:69 as monitored by19F NMR spectroscopy of 5-fluorouracil-substituted tRNAVal [4].
• Added spermidine has the curious effect of increasing the exchange rate of the psi 55 N1 proton, while protecting the psi 55 N3 proton from exchange in all three tRNA's. Added Mg++ has the same effect on tRNAVal [1].
• The nucleotide sequence of a spinach chloroplast valine tRNA (sp. chl. tRNA Val) has been determined [5].

Biological context of tRNA-Val

• Yeast tRNA Val 1 alkylation with 2', 3'-O-4-(N-2-chloroethyl-N-methylamino) benzylidene d(pC-G)-A proceeds at 20 degrees - 30 degrees C in the complementary complexes which are formed by d(pC-G)-A greater than RC1 binding to 3 sequences of tRNA Val 1 : psi-C-G58 in the T loop, C-G40 at the 3'-side of the anticodon loop and C-G18 in the D loop [6].
• It is the third nucleotide from the 5'-terminus of the binding site of the modifying agent that is subjected to alkylation in the t RNA Val 1 [6].
• Catalytic mechanism of valyl-tRNA synthetase from baker's yeast. Reaction pathway and rate-determining step in the aminoacylation of tRNAVal [7].

Associations of tRNA-Val with chemical compounds

• Valyl-tRNA synthetase, as well as activating a number of amino acid analogues, will accept alanine, cysteine, isoleucine, and serine in addition to threonine as substrates for both ATP-PPi exchange and transfer to some tRNAVal species [8].
• The properties of native and of two modified tRNA Val species in the correction of misactivated threonine by valyl-tRNA synthetase have been studied [9].
• We show that after the fast transfer of valine from adenylate to tRNAVal, followed by the fast dissociation of AMP and PPi, a new adenylate is synthesized which promotes the dissociation of the nascent Val-tRNAVal [7].
• Isoleucyl-tRNA synthetase from bakers' yeast: variable discrimination between tRNAIle and tRNAVal and different pathways of cognate and noncognate aminoacylation under standard conditions, in the presence of pyrophosphatase, elongation factor Tu-GTP complex, and spermine [10].

Other interactions of tRNA-Val

• Anticodon-anticodon interactions in solution. Studies of the self-association of yeast or Escherichia coli tRNAAsp and of their interactions with Escherichia coli tRNAVal [11].
• The overall discrimination factor was first determined by isoleucylation of tRNAVal/tRNAIle mixtures [10].
• Nearly 100% protection was found in the anticodon and acceptor stem of tRNAVal, while in tRNAPhe only the stem of the anticodon was protected [12].

Analytical, diagnostic and therapeutic context of tRNA-Val

• Ultracentrifugation studies of yeast valyl-tRNA synthetase and of its interaction with tRNAVal [13].

References