Escherichia coli K-12 substr. MG1655 tRNA: tRNAvalX

Gene: valX Accession Numbers: EG30113 (EcoCyc), b2402, ECK2396

Synonyms: valU-beta, valUbeta

Superclasses: a tRNAval

Regulation Summary Diagram: ?

Regulation summary diagram for valX

tRNA(valX) is one of seven valine tRNAs.

tRNAs are the adapters that allow synthesis of proteins from mRNAs. Each tRNA carries a specific amino acid to the ribosome for protein synthesis. There, the tRNA recognizes an RNA codon with its own three-nucleotide anticodon, thus allowing synthesis of a specific peptide based on an mRNA template. In the case of tRNA(val), all seven species appear to recognize all four valine codons. Mitra1977 319094

tRNAs are processed to their active, mature forms by RNA cleavage and by modification of their bases. RNA cleavage consists of removal of both 5' and 3' extensions in a multistep process involving many RNases [Morl01]. RNases taking part in tRNA processing include ribonuclease E, RNase BN, RNase D, ribonuclease II, and RNase T. tRNAs are also subject to a wide variety of base modifications catalyzed by proteins such as tRNA-dihydrouridine synthase A, tRNA(i6A37) synthase, isopentenyl-adenosine A37 tRNA methylthiolase, tRNA-specific 2-thiouridylase, fused 5-methylaminomethyl-2-thiouridine-forming methyltransferase and FAD-dependent demodification enzyme, tRNA-guanine transglycosylase, tRNA m7G46 methyltransferase, tRNA pseudouridine 13 synthase, tRNA pseudouridine 65 synthase, tRNA pseudouridine 55 synthase, tRNA pseudouridine synthase I, tRNA (Gm18) 2'-O-methyltransferase, and tRNA m5U54 methyltransferase.

Mature tRNAs are linked via a 3' CCA sequence to their cognate amino acid in an ATP-dependent fashion by the appropriate amino-acid-tRNA synthetase, as shown in the tRNA charging. Subsequently, these charged tRNAs interact with the ribosome and template mRNA to generate polypeptides. The discovery of the role of tRNA in protein synthesis is reviewed in detail in [Siekevitz81].

tRNA(val) has been a favorite target of NMR studies [Hare82a, Hare85]. It has been evaluated via C-13 NMR [Schweizer80, Olsen82]. C-13 NMR has specifically been applied to detecting the dynamics of free tRNA(val) and its interaction with valyl-tRNA synthetase [Schweizer84]. NMR has been used to track the stabilizing effects of ions on tRNA(val) structure, with additional study done using other spectroscopic techniques [Kastrup78, Taherian81, Thomas84].

Map Position: [2,519,073 -> 2,519,148] (54.29 centisomes, 195°)
Length: 76 bp

Anticodon: UAC

Reactions known to consume the compound:

tRNA charging :
a tRNAval + L-valine + ATP + H+ → an L-valyl-[tRNAval] + AMP + diphosphate

Reactions known to produce the compound:

tRNA processing :
a tRNA precursor with a short 3' extension → an uncharged tRNA + n a nucleoside 5'-monophosphate
a tRNA precursor with a short 3' extension + n phosphate → an uncharged tRNA + n a ribonucleoside diphosphate
a tRNA precursor with a 5' extension + H2O → an uncharged tRNA + a single-stranded RNA

Not in pathways:
an N-modified aminoacyl-[tRNA] + H2O → an uncharged tRNA + an N-modified amino acid + 2 H+
a D-aminoacyl-[tRNA] + H2O → a D-amino acid + an uncharged tRNA + 2 H+

Not in pathways:
a tRNA precursor + H2O → a tRNA + a nucleoside 5'-monophosphate

tRNA processing :
a tRNA precursor with a 5' extension and a short 3' extension + H2O → a tRNA precursor with a short 3' extension + a single-stranded RNA
a tRNA precursor with a 5' extension + H2O → an uncharged tRNA + a single-stranded RNA

Not in pathways:
YhaV endonuclease degradation substrate mRNA + H2O → 2 a single-stranded RNA
an mRNA + H2O → a single-stranded RNA + a single-stranded RNA
an mRNA + H2O → a single-stranded RNA + a single-stranded RNA
RNase E degradation substrate mRNA + n H2O → n a single-stranded RNA
YhaV endonuclease degradation substrate rRNA + H2O → 2 a single-stranded RNA
RNase III mRNA processing substrate + 2 H2O → RNase III processing product mRNA + 2 a single-stranded RNA
23S rRNA[periplasmic space] + H2O[periplasmic space] → 2 a single-stranded RNA[periplasmic space]
an mRNA[periplasmic space] + H2O[periplasmic space] → 2 a single-stranded RNA[periplasmic space]
RNase G degradation substrate mRNA + H2O → 2 a single-stranded RNA
9S rRNA + 2 H2O → 5S rRNA + 2 a single-stranded RNA
RNase E mRNA processing substrate + n H2O → RNase E processing product mRNA + n a single-stranded RNA

Reactions known to both consume and produce the compound:

Not in pathways:
a single-stranded RNA + phosphate ↔ a single-stranded RNA + a nucleoside diphosphate

In Reactions of unknown directionality:

Not in pathways:
rRNA[periplasmic space] = 2 a single-stranded RNA[periplasmic space]

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Genetic Regulation Schematic: ?

Genetic regulation schematic for valX

Unification Links: ASAP:ABE-0007916 , CGSC:28696 , EchoBASE:EB4276 , EcoGene:EG30113 , EcoliWiki:b2402 , OU-Microarray:b2402 , PortEco:valX , RegulonDB:EG30113

GO Terms:

Molecular Function: GO:0030533 - triplet codon-amino acid adaptor activity
Cellular Component: GO:0005737 - cytoplasm
GO:0005829 - cytosol

MultiFun Terms: information transfer RNA related tRNA

Transcription Units regulated by related protein L-valyl-tRNAvalX (3 total):

Transcription-unit diagram

Transcription-unit diagram

Transcription-unit diagram

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Units:

Transcription-unit diagram

Transcription-unit diagram

Transcription-unit diagram

Transcription-unit diagram


10/20/97 Gene b2402 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG30113.

Last-Curated ? 26-Apr-2006 by Shearer A , SRI International


Hare82a: Hare DR, Reid BR (1982). "Direct assignment of the dihydrouridine-helix imino proton resonances in transfer ribonucleic acid nuclear magnetic resonance spectra by means of the nuclear Overhauser effect." Biochemistry 21(8);1835-42. PMID: 6282322

Hare85: Hare DR, Ribeiro NS, Wemmer DE, Reid BR (1985). "Complete assignment of the imino protons of Escherichia coli valine transfer RNA: two-dimensional NMR studies in water." Biochemistry 24(16);4300-6. PMID: 3902082

Kastrup78: Kastrup RV, Schmidt PG (1978). "1H NMR of valine tRNA modified bases. Evidence for multiple conformations." Nucleic Acids Res 5(1);257-69. PMID: 347397

Morl01: Morl M, Marchfelder A (2001). "The final cut. The importance of tRNA 3'-processing." EMBO Rep 2(1);17-20. PMID: 11252717

Olsen82: Olsen JI, Schweizer MP, Walkiw IJ, Hamill WD, Horton WJ, Grant DM (1982). "Carbon-13 NMR relaxation studies of pre-melt structural dynamics in [4-13C-uracil] labeled E. coli transfer RNAIVal." Nucleic Acids Res 10(14);4449-64. PMID: 6750556

Schweizer80: Schweizer MP, Hamill WD, Walkiw IJ, Horton WJ, Grant DM (1980). "Carbon-13 NMR studies on [4-13C] uracil labelled E. coli transfer RNA1(Val1)." Nucleic Acids Res 8(9);2075-83. PMID: 7001371

Schweizer84: Schweizer MP, Olsen JI, De N, Messner A, Walkiw I, Grant DM (1984). "13C NMR studies of dynamics and synthetase interaction of [4-13C]uracil-labeled Escherichia coli tRNAs." Fed Proc 43(15);2984-6. PMID: 6389182

Siekevitz81: Siekevitz P, Zamecnik PC (1981). "Ribosomes and protein synthesis." J Cell Biol 91(3 Pt 2);53s-65s. PMID: 7033244

Taherian81: Taherian MR, Maki AH (1981). "Optically detected magnetic resonance of the phosphorescent bases of Escherichia coli valine-specific transfer ribonucleic acid." Biochemistry 20(25);7295-301. PMID: 7032589

Thomas84: Thomas JC, Schurr JM, Reid BR, Ribeiro NS, Hare DR (1984). "Effect of Mg2+ on solution conformation of two different transfer ribonucleic acids." Biochemistry 23(23);5414-20. PMID: 6210103

Other References Related to Gene Regulation

Champagne98: Champagne N, Lapointe J (1998). "Influence of FIS on the transcription from closely spaced and non-overlapping divergent promoters for an aminoacyl-tRNA synthetase gene (gltX) and a tRNA operon (valU) in Escherichia coli." Mol Microbiol 1998;27(6);1141-56. PMID: 9570400

Neidhardt96: Neidhardt FC, Curtiss III R, Ingraham JL, Lin ECC, Low Jr KB, Magasanik B, Reznikoff WS, Riley M, Schaechter M, Umbarger HE "Escherichia coli and Salmonella, Cellular and Molecular Biology, Second Edition." American Society for Microbiology, Washington, D.C., 1996.

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
Page generated by SRI International Pathway Tools version 19.0 on Fri Mar 27, 2015, biocyc14.