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

We have determined the structure and complete nucleotide sequence of the trifunctional trpC gene from the Ascomycetous fungus Aspergillus nidulans. Results from RNA gel blot analyses showed that this gene encodes two size classes of polyribosomal, poly (A)+RNAs with approximate lengths of 2,400 and 2,600 nucleotides. S1 nuclease protection studies demonstrated that the distribution into the two size classes is due to selection of alternative sites for polyadenylation. The transcription units contain a single open translation reading frame of 2,304 nucleotides. The sequence of this reading frame is approximately 40% divergent from the sequence of the functionally analogous trp-1 gene from Neurospora crassa (Schechtman, M.G. and Yanofsky, C., J. Mol. Appl. Gen. 2:83-99). The predicted amino acid sequence of the A. nidulans trpC polypeptide is also 40% divergent from the predicted amino acid sequence of the N. crassa trp-1 polypeptide. The A. nidulans gene has considerably less bias in codon selection than observed for the N. crassa gene. Discrete regions of DNA homology were also found in similar positions in the 5' and 3' flanking sequences of the Aspergillus and Neurospora genes. Similar regions of homology were not observed in other Aspergillus or Neurospora genes that have been sequenced. Thus, if these evolutionarily conserved sequences act as signals for transcription initiation or polyadenylation, or are involved in gene regulation, their functions are restricted to a subset of protein coding genes in these two closely related fungi.
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PMID:Primary structure of the trpC gene from Aspergillus nidulans. 315 96

The trifunctional trp-1 gene from Neurospora crassa was cloned by complementation of a phosphoribosylanthranilate isomerase-deficient mutant of E. coli. A 2.7-kb DNA sequence containing trp-1 was determined. Homology of the deduced trp-1 polypeptide sequence to the corresponding E. coli proteins is striking; the order of functional domains within trp-1 is NH2-glutamine amidotransferase-indoleglycerolphosphate synthase-phosphoribosylanthranilate isomerase-COOH (NH2-trpG-trpC-trpF-COOH). Whereas trpF complementing activity can be detected in E. coli, trpC activity is absent. It is likely that translation of trp-1 does not proceed from the proper start site in E. coli; the carboxy terminal portion of the trp-1 polypeptide may be the only portion synthesized. Fusion of a bacterial amino terminus and ribosome binding site to the trp-1 coding region results in expression of trpC as well as trpF activity in E. coli. The locations of several startpoints for trp-1 mRNA synthesis were determined by the S1 nuclease mapping technique. DNA immediately 5' to the trp-1 transcription initiation region does not possess a sequence resembling the canonical TATAAA of eukaryotes.
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PMID:Structure of the trifunctional trp-1 gene from Neurospora crassa and its aberrant expression in Escherichia coli. 622 Oct 60