Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The four major adeno-associated virus type 2 (AAV2)-specific RNAs were mapped on the linear viral genome by a variety of biochemical techniques, including S1 nuclease and exonuclease VII mapping, RNA gel-transfer hybridization, and analysis of reverse transcriptase extension products. All the major AAV2 RNAs were derived from the minus DNA strand and had 3' termini at position 96. The nucleus-specific 4.3- and 3.6-kilobase (kb) RNAs had 5' termini at positions 6 and 19, respectively. The 5' terminus of the 2.6-kb RNA mapped to position 38.5. The predominant 2.3-kb AAV2 mRNA was spliced and contained a short leader sequence (approximately 50 nucleotides) which mapped to position 38.5, coincident with the 5' terminus of the 2.6-kb RNA. The 5' end of the body of the 2.3-kb RNA mapped to position 46.5. These results are discussed in terms of the involvement of single versus multiple promoters (for transcription) and RNA splicing mechanisms in the generation of the AAV2 RNAs.
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PMID:Transcripts of the adeno-associated virus genome: mapping of the major RNAs. 625 15

The promoter of the gua operon has been located by transcript mapping using primer extension with reverse transcriptase. The surrounding nucleotide sequence has features characteristic of promoters under stringent and growth-rate-dependent regulation, namely a GC-rich discriminator next to the -10 hexamer, an upstream AT-rich sequence (the UP element) and potential FIS-binding sites. Transcriptional activity of the gua promoter was examined using transcriptional fusions to lacZ placed at a single chromosomal location. Expression from gua was reduced under stringent conditions in vivo, and varied with growth rate. Growth-rate control was independent of guanine-mediated repression. A fusion in which the GC-rich discriminator was mutated by insertion of an AT-rich oligonucleotide was used to demonstrate the importance of this region in control. Both stringent and growth-rate-dependent controls were abolished by the mutation. Other potential regulatory signals in the vicinity of the gua promoter are a pur operator (binding site for the PurR repressor), a gua operator, a DnaA-binding site and a CRP/FNR-binding sequence. The gua promoter lies back-to-back with the promoter for xseA (exonuclease VII), the two promoters being separated by only 20 bp.
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PMID:Stringent and growth-rate-dependent control of the gua operon of Escherichia coli K-12. 882 9