Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.2.1.7 (BAL)
 1,977 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The complete nucleotide sequence of the Clostridium thermocellum celE gene, coding for an endo-beta-1,4-glucanase (endoglucanase E; EGE) with xylan-hydrolysing activity has been determined. The structural gene consists of an open reading frame (ORF) of 2442 bp commencing with a GTG start codon and followed by a TAA stop codon. The nucleotide sequence obtained has been confirmed by comparing the predicted amino acid sequence with that derived by N-terminal amino acid sequencing of the purified protein. The EGE sequence contains a region homologous to the reiterated domain found at the C terminus of other endoglucanases from the same organism. BAL 31 deletions of the structural gene have revealed the extent to which this conserved sequence is necessary for endoglucanase and xylanase activity. A region of DNA, upstream from the structural gene has also been sequenced and a ribosome-binding site and putative promoter sequences have been identified. A second ORF which ends 349 bp 5' to the GTG start codon of the celE gene has also been identified. The encoded product contains a C terminus homologous to other C. thermocellum endoglucanases.
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PMID:Conserved reiterated domains in Clostridium thermocellum endoglucanases are not essential for catalytic activity. 306 98

An Escherichia coli-mycobacterial shuttle vector, pJCluc, containing a luciferase reporter gene, was constructed and used to analyse the Mycobacterium tuberculosis katG promoter. A 1.9 kb region immediately upstream of katG promoted expression of the luciferase gene in E. coli and Mycobacterium smegmatis. A smaller promoter fragment (559 bp) promoted expression with equal efficiency, and was used in all further studies. Two transcription start sites were mapped by primer extension analysis to 47 and 56 bp upstream of the GTG initiation codon. Putative promoters associated with these show similarity to previously identified mycobacterial promoters. Deletions in the promoter fragment, introduced with BAL-31 nuclease and restriction endonucleases, revealed that a region between 559 and 448 bp upstream of the translation initiation codon, designated the upstream activator region (UAR), is essential for promoter activity in E. coli, and is required for optimal activity in M. smegmatis. The katG UAR was also able to increase expression from the Mycobacterium paratuberculosis P(AN) promoter 15-fold in E. coli and 12-fold in M. smegmatis. An alternative promoter is active in deletion constructs in which either the UAR or the katG promoters identified here are absent. Expression from the katG promoter peaks during late exponential phase, and declines during stationary phase. The promoter is induced by ascorbic acid, and is repressed by oxygen limitation and growth at elevated temperatures. The promoter constructs exhibited similar activities in Mycobacterium bovis BCG as they did in M. smegmatis.
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PMID:The Mycobacterium tuberculosis katG promoter region contains a novel upstream activator. 1051 3