Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The gene coding for Escherichia coli arginyl-tRNA synthetase (argS) was isolated as a fragment of 2.4 kb after analysis and subcloning of recombinant plasmids from the Clarke and Carbon library. The clone bearing the gene overproduces arginyl-tRNA synthetase by a factor 100. This means that the enzyme represents more than 20% of the cellular total protein content. Sequencing revealed that the fragment contains a unique open reading frame of 1734 bp flanked at its 5' and 3' ends respectively by 247 bp and 397 bp. The length of the corresponding protein (577 aa) is well consistent with earlier Mr determination (about 70 kd). Primer extension analysis of the ArgRS mRNA by reverse transcriptase, located its 5' end respectively at 8 and 30 nucleotides downstream of a TATA and a TTGAC like element (CTGAC) and 60 nucleotides upstream of the unusual translation initiation codon GUG; nuclease S1 analysis located the 3'-end at 48 bp downstream of the translation termination codon. argS has a codon usage pattern typical for highly expressed E. coli genes. With the exception of the presence of a HVGH sequence similar to the HIGH consensus element, ArgRS has no relevant sequence homologies with other aminoacyl-tRNA synthetases.
 ...
PMID:Isolation and characterization of the gene coding for Escherichia coli arginyl-tRNA synthetase. 266 91

IMP dehydrogenase, the product of the guaB locus in Escherichia coli K12, catalyzes the synthesis of XMP by the NAD+ dependent oxidation of IMP. The guaB locus has been subcloned from the Clarke and Carbon plasmid pLC34-10. The sequence of the guaB structural gene and surrounding DNA was determined by the dideoxy chain termination method of Sanger. The 1.533 kb guaB gene encodes an IMP dehydrogenase subunit of molecular weight 54,512. S1 nuclease mapping placed the site of guaBA mRNA initiation approximately 188 bp from the start of the guaB structural gene. The -10 and -35 regions that define the guaBA promoter were located upstream of the start of the guaBA transcription initiation site. The control region of approximately 188 bp does not show any obvious potential for secondary structure. A secondary lambda att site has been identified 42 bp distal to the guaB start codon.
 ...
PMID:Nucleotide sequence of the guaB locus encoding IMP dehydrogenase of Escherichia coli K12. 286 Jun 37

Escherichia coli relB mutants react to amino acid starvation by several abnormal responses, including accumulation of a translational inhibitor. We have isolated a relB-complementing plasmid from the Clarke and Carbon E. coli DNA library. From this plasmid we sequenced a 2140-bp segment which included the relB gene by the following two criteria: (i) it complements chromosomal relB mutations, (ii) the corresponding DNA segment cloned from chromosomal DNA of three relB mutants was defective in relB complementation. All three mutations fell within an open reading frame of 79 amino acids. A polypeptide of 9 kd compatible with this open reading frame was synthesized in maxicells and is in all probability the product of the relB gene. By nuclease S1 mapping we have determined the transcription start and stop of an 870 base transcript of the relB gene.
 ...
PMID:Sequence of the relB transcription unit from Escherichia coli and identification of the relB gene. 299 Sep 7

We report the subcloning and characterization of the molecular elements necessary for the expression of the Escherichia coli valS gene which encodes the enzyme valyl-tRNA synthetase (EC 6.1.1.9). The valS gene was subcloned from the Clarke-Carbon plasmid pLC26-22 by genetic complementation of the valS temperature-sensitive mutant strain, AB4141. The protein-coding region of the valS structural gene was determined by in vitro DNA directed coupled transcription-translation assays. Assays of cellular extracts of cells transformed with a plasmid containing a full length copy of the valS gene enhanced in vivo valyl-tRNA synthetase-specific activity 12-fold. The DNA sequences of the 5'- and 3'-terminal regions of the valS structural gene are presented. The transcription initiation sites of the valS gene were determined, in vivo and in vitro, by S1 nuclease protection studies, primer-extension analysis and both alpha-32P labeled and gamma-32P-end-labeled in vitro transcription assays. In vivo, valS transcription initiates from tandem overlapping promoters separated by seven nucleotides. In vitro, only the upstream promoter is active. The presence of several regions of hyphenated dyad symmetry overlapping the tandem promoter region are noted. The valS translational start codon (AUG) is located 93 base pairs downstream from the major transcription initiation site. The valS transcriptional unit encodes only the valyl-tRNA synthetase gene since the 3' terminus of the amino acid-coding region of this gene is followed closely (26 base pairs) by an efficient rho-independent transcription termination site.
 ...
PMID:Valyl-tRNA synthetase gene of Escherichia coli K12. Molecular genetic characterization. 327 59

GMP synthetase (EC 6.3.4.1), a glutamine amido-transferase encoded by the guaA gene, catalyzes the synthesis of GMP from XMP. The guaA gene was subcloned from the Clarke and Carbon (Clarke, L., and Carbon, J. (1976) Cell 9, 91-99) plasmid pLC34-10, and the nucleotide sequence was determined. The structural gene encodes a protein of 525 amino acid residues having a calculated Mr of 58,604. The amino acid sequence of the NH2 terminus of GMP synthetase was determined and used to verify the translation start site determined from the DNA sequence. A 68-base pair intercistronic region separates guaA from the upstream guaB gene in the polycistronic guaBA operon. The 3' end of the guaA mRNA was determined by S1 nuclease mapping. The 3' end of guaA mRNA is 36-37 nucleotides downstream of the translation stop codon within a region of dyad symmetry that resembles a rho-independent transcription termination site.
 ...
PMID:Nucleotide sequence of the guaA gene encoding GMP synthetase of Escherichia coli K12. 389 45

From a Clark-Carbon plasmid containing trpS, the structural gene for the tryptophanyl-transfer ribonucleic acid synthetase of Escherichia coli, we subcloned a 2.6-kilobase fragment that has trpS and its neighboring regions. The location and orientation of trpS in the deoxyribonucleic acid insert was determined by deoxyribonucleic acid sequencing. In vitro transcription experiments and S1 nuclease mapping studies with in vivo message established that transcription is initiated at the same site in vivo and in vitro, approximately 58 base pairs upstream from the trpS coding region. We also describe the construction of an inphase trpS-lacZ gene fusion that is under the control of the trpS promoter and encodes a hybrid protein with beta-galactosidase activity.
 ...
PMID:Cloning and characterization of the gene for Escherichia coli tryptophanyl-transfer ribonucleic acid synthetase. 617 61

Carbon nanotubes (CNTs) can efficiently quench the fluorescence of the adsorbed fluorophores and nonconvalently interact with soft single-stranded DNA (ssDNA). Upon disruption of CNTs-fluorescent oligonucleotides hybrid by nuclease S1, fluorescence turn-on was observed. Using this strategy, a platform based on fluorescence signal for monitoring the activity of nuclease with advantages of high sensitivity and commonality was established, and a linear relationship between initial cleavage reaction rate and nuclease S1 concentration is found in the range of 0.6-8.0 U mL(-1) with a detection limit of 0.08 U mL(-1). Furthermore, by taking pyrophosphate as an example, we use the assay to evaluate the prohibition effect on nuclease, and the extent of fluorescence recovery decreased linearly with increasing the concentration of pyrophosphate in the range of 0.2-1.4 mM, implying that the cleavage reaction by nuclease S1 was prohibited, and therefore this fluorescence assay can also be conveniently utilized for inhibitor screening of nuclease.
 ...
PMID:Carbon nanotube-DNA hybrid used for activity monitoring and inhibitor screening of nuclease. 2199 25