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 leading region of the Escherichia coli K12 F plasmid is the first segment of DNA to be transferred into the recipient cell during conjugal transfer. We report the nucleotide sequence of the 64.20-66.77F portion of the leading region immediately adjacent to the origin of transfer, oriT. The 2582 bp region encodes three open reading frames, ORF95, ORF169 and ORF273; the product of ORF273, is equivalent in size and map location to the 35 kDa protein, 6d, previously described (Cram et al. 1984). S1 nuclease analyses of mRNA transcripts have identified a potential promoter for ORF95 and ORF273 and indicated that these ORFs are transcribed as a single transcript; in contrast, ORF169 appears to be transcribed from two overlapping promoters on the complementary DNA strand. The products of ORF95 and ORF273 are mainly hydrophilic and are probably located in the cytoplasm. ORF273 shares some homology with DNA-binding proteins. There is a signal peptide sequence at the NH2-terminus of ORF169 and the mature form of ORF169 probably resides in the periplasm due to its hydrophilic nature. Both ORF273 and ORF169 are well conserved among conjugative F-like and a few non-F-like plasmids. On the other hand, ORF95 sequences are only present on some of these plasmids. Several primosome and integration host factor recognition sites are present implicating this region in DNA metabolism and/or replication functions.
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PMID:Nucleotide sequence of the leading region adjacent to the origin of transfer on plasmid F and its conservation among conjugative plasmids. 269 41

Streptomyces halstedii JM8 Cel2 is an endoglucanase of 28 kDa that is first produced as a protein of 42 kDa (p42) and is later processed at its C-terminus. Cel2 displays optimal activity towards CM-cellulose at pH6 and 50 degrees C and shows no activity against crystalline cellulose or xylan. The N-terminus of p42 shares similarity with cellulases included in family 12 of the beta-glycanases and the C-terminus shares similarity with bacterial cellulose-binding domains included in family II. This latter domain enables the precursor to bind so tightly to Avicel that it can only be eluted by boiling in 10% (w/v) SDS. Another open reading frame (ORF) situated 216 bp downstream from the p42 ORF encodes a protein of 40 kDa (p40) that does not have any clear hydrolytic activity against cellulosic or xylanosic compounds, but shows high affinity for Avicel (crystalline cellulose). The p40 protein is processed in old cultures to give a protein of 35 kDa that does not bind to Avicel. Translation of both ORFs is impaired in Streptomyces coelicolor bldA mutants, suggesting that a TTA codon situated at the fourth position of the first ORF is responsible for this regulation. S1 nuclease protection experiments demonstrate that both ORFs are co-transcribed.
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PMID:Two genes encoding an endoglucanase and a cellulose-binding protein are clustered and co-regulated by a TTA codon in Streptomyces halstedii JM8. 918 97